An excitable device for wireless sensing applications

Abstract

The disclosure provides an excitable device for detecting at least one physical and / or chemical parameter, the excitable device comprising: at least one oscillating magnet configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; a connecting body having one part coupled to the at least one oscillating magnet; a housing component; and a sensing material configured to change at least one mechanical property in response to the at least one physical and / or chemical parameter; wherein the excitable device is configured such that a change of the at least one mechanical property of the sensing material changes how the at least one oscillating magnet oscillates; and wherein the connecting body and the at least one oscillating magnet are isolated, preferably chemically and / or mechanically, from a surrounding medium by the housing component or by a combination of the housing component and the sensing material.

Description

[0001] New PCT Patent Application Vossius & Partner Deutsches Krebsforschungszentrum Patentanwalte Rechtsanwalte mbB Stiftung des offentlichen Rechts SiebertstraRe 3 DKFZ Ref: P12007PC01 81675 Munchen

[0002] Vossius Ref.: AJ2939 PCT May 23, 2025

[0003] AN EXCITABLE DEVICE FOR WIRELESS SENSING APPLICATIONS

[0004] The present disclosure relates to a method, an excitable device, and a system for obtaining (detecting) at least one physical and / or chemical parameter.

[0005] It is of general interest to measure physical or chemical quantities of an environment, especially in a wireless manner. In many cases, such as in the human body, it is advantageous or necessary to have a high accuracy, use a minimal footprint of the device, have wireless functionality without on-board power, and being able to measure multiple parameters at once. In many state-of-the-art devices, only a few of these requirements are met.

[0006] The following illustrates the state-of-the-art wireless sensors. Such sensors require a wireless modality of energy reception, -storage, and -transmission and an on-board feature which is sensitive to the desired parameter.

[0007] I ngestible capsule sensors [1] use radio-frequency (RF) antennas to transmit data. Energy can be provided to the system via RF coils or on-board batteries. Both inherently occupy large volumes (>900 mm3), limiting the miniaturization of the overall capsule. Due to their size, they are undesired for implantation directly into human tissues and are mostly used for gastrointestinal or wearable-electronics applications. Additionally, RF signals are attenuated by biological media, further reducing their functionality in vivo.

[0008] Wireless bio / -chemical sensors [2] can determine the pH or the concentration of glucose, ions and other chemicals. Due to large size of the electronic circuitry and on-board energy modules, they are mostly used for wearable applications. Most aforementioned sensors are not capable of measuring multiple parameters at once. [3] to

[0011] illustrate the use of magneto-oscillatory devices for sensing of pressure and temperature, developed by Philips GmbH Innovative Technologies Research Laboratories Hamburg. Here, two magnetic spheres are arranged within a device such that at least one of the magnets is attached to a string while being suspended by the magnetic attraction to the second magnet. The magnet attached to the string can be excited by an external magnetic field, which induces an oscillation about the magnet's axis. Herein, the term "external" refers to any space outside a defined space, e.g., a housing or excitable device comprising said magnet which is being excited by the exciting magnetic field, unless otherwise specified.

[0009] The system of [3] to

[0011] exhibits a magnetic signal resonance frequency which is dependent on the distance between the two magnets. Hence, when the distance between the two spheres is changed, the resonance frequency of the system changes. This can be implemented for pressure by a bellow structure. Similarly, for temperature, the suspension string changes dimensions which leads to a frequency shift.

[0010] However, there are multiple disadvantages of the said device: 1) it utilizes at least two magnets, which has a complicated structure and difficulty in miniaturization; 2) it discloses the way of sensing only physical parameters, i.e. temperature and pressure, but does not demonstrate chemical, especially biochemical sensing; 3) as the frequency is the only parameter that is changed, this device can only measure one parameter at a time.

[0011] Thus, there is a need to improve a method, an excitable device, and a system for obtaining at least one physical and / or chemical parameter. The above-mentioned disadvantages are at least partly overcome and / or advantages mentioned herein are at least partly achieved with the features of the independent claims. Dependent claims define preferred embodiments of the present disclosure.

[0012] The following discusses the magneto-oscillatory devices, in particular the characteristics, the parameters involved, and the utilization thereof. Basics of magneto-oscillatory devices:

[0013] Magneto-oscillatory devices are mechanically resonant systems which are coupled with permanent magnets. In reference to FIG. 1, said system may, e.g., comprise a cantilever 120 having one side fixed to an object or ground 110 and another side fixed to a permanent magnet 130. Herein, the term "permanent magnet" is interchangeably used with the terms "magnet", "oscillating magnet", and "oscillating permanent magnet", unless otherwise specified. The magnet 130 acts as oscillating mass, as energy-receiver, and as signaltransmitter. The cantilever-mass system is the energy-storage unit.

[0014] By applying an oscillating or pulsed external magnetic field Bext (or mechanical force) perpendicular to the magnet's magnetic moment direction at the systems mechanical resonance frequencyres, the magnet deflects periodically with an increasing deflection angle 0. Once a desired angle 0 or the maximum angle 0max is reached, the excitation is stopped by turning off the excitation field Bext. At this stage, the energy is mechanically stored inside the cantilever-mass system. The deflected, or bent, cantilever 121 and magnet 131 forming the deflection angle 0 with respect to the stationary cantilever 120 and magnet 130 are shown with dotted lines in FIG. 1.

[0015] The energy is released by the periodic deflection according to an exponentially damped harmonic oscillator with frequency fresand damping coefficient 6:

[0016] 0( = 0max * C0s(27Trest + 0) * exp(-<5t) (1) wherein t denotes time and 0 denotes phase shift. Meanwhile, since the magnet's magnet field is directly coupled to the resonator, a signal is transmitted which can be measured by a magnetometer. The measured signal B is comparable to that of an exponentially damped harmonic oscillator and can be approximated as such for certain orientations between the oscillating magnet and magnetometer:

[0017] B(t) = A * cos(27rrest + 0) * exp(— 8t) (2) Oscillation parameters of magneto-oscillatory devices:

[0018] The oscillation of magneto-oscillatory devices can be influenced by the resonance frequency fres. The natural frequency f0(i.e., resonance frequency without damping) of the mechanical system is that of a typical cantilever-mass system with wherein kc denotes the spring constant of the cantilever and mmogdenotes the mass of the magnet. The spring constant itself is dependent on the cantilever material and dimensions, the magnet's mass is dependent on the volume and density of the magnet.

[0019] Contactless" modification of oscillation parameters:

[0020] Parameterresof the magneto-oscillatory system can be modified with complete reversibility without mechanical contact to the system. In reference to FIG. 2, the resonance frequency can be modified by applying a static magnetic field to the oscillating magnet 230, either by an additional permanent magnet 240 which is different from the oscillating magnet 230, by an electromagnetic coil (omitted in FIG. 2), or other magnetic fields. Magnetic gradients can also affect the resonance frequency of the system. The structural configuration and the physical characteristics of the object or ground 210, cantilever 220, and the magnet 230 in FIG. 2 are the same as those of the respective object or ground 110, cantilever 120, and the magnet 130 in FIG. 1. Depending on the orientation, distance d, and strength of the additional magnetic field or gradient, frescan be increased or decreased over a wide range (e.g. >10% of the initial fres). The excitation frequency has to be adjusted accordingly to ensure a large deflection and signal amplitude. [3] describes and uses this method. The non-linear relationship between fresand d3, wherein d in FIG. 2 denotes the distance between the oscillating magnet 230 and the additional permanent magnet 240, is described in

[0012] , Functionalization of the parameters:

[0021] This principle can be functionalized by functionalizing the distance d between the respective components by placing the additional permanent magnet 240 to a deformable unit, which is sensitive to an external parameter. One example such for a deformable unit is a bellow structure which deforms by application of pressure (see [3]). The corresponding signal parameter fresis thereby sensitive to pressure. Another example is a hydrogel which swells in acidic or basic conditions, depending on the pH-value, creating a pH-sensitive signal parameter. The options for deformable units are manifold and could be applied for temperature (proven by [3]), humidity, forces, chemicals, antibodies, and so on.

[0022] "Direct-contact" modification of oscillation parameters

[0023] It is also possible to modify fresby varying the mass mmag of the oscillating component or magnet, or by changing the spring constant kc of the elastic component as shown in Eq. (3). Due to the direct mechanical coupling, it is possible influence the damping parameter 6 as well. This is presented in

[0013] for a translating magnet attached to a membrane. The oscillating mass and membrane are in direct mechanical contact with the environment, and the oscillating mass comprises a magnet and a component, which is sensitive to the environment. Depending on chemical cues, e.g. glucose, the sensitive component gains mass and thereby influences fres. The elastic membrane is sensitive to changes of viscosity and elasticity of the environment. However, the magnetic signal decays quickly due to the large contact area of the membrane with the environment and the coupling of the oscillating component to the environment, which increases energy dissipation dramatically. Furthermore, translation of a magnet produces weaker signals than rotation while occupying a larger oscillation volume, making this method inefficient for miniaturization.

[0024] Generally, a direct mechanical contact of the oscillating components to the environment is undesired because of very strong signal attenuation in viscoelastic environments, e.g. biological soft tissues, easier fracture / rupture / breaking of the elastic component from unforeseen sudden environmental changes, e.g. too high pressure, bones disintegration of the structure from an immune response or faster degradation

[0025] Hence, it is beneficial to not expose the elastic component and oscillation mass directly to the environment, but instead to provide a cavity, filled with e.g. air or vacuum, for the elastic component and oscillation mass, as shown in [3]-[ll].

[0026] Summary of the invention

[0027] The present disclosure relates to an excitable device for detecting at least one physical and / or chemical parameter, the excitable device comprising: at least one oscillating magnet configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; a connecting body having one part coupled to the at least one oscillating magnet; a housing component; and a sensing material configured to change at least one mechanical property in response to the at least one physical and / or chemical parameter; wherein the excitable device is configured such that a change of the at least one mechanical property of the sensing material changes how the at least one oscillating magnet oscillates; and wherein the connecting body and the at least one oscillating magnet are isolated, preferably chemically and / or mechanically, from a surrounding medium by the housing component or by a combination of the housing component and the sensing material.

[0028] Various embodiments may preferably implement the following features.

[0029] Additional or alternative to the mechanical properties, this may also work for dimensional properties. This may mean that the sensing material is configured to change at least one mechanical property and / or dimension in response to the at least one physical and / or chemical parameter; and wherein the excitable device is configured such that a change of the at least one mechanical property and / or dimension of the sensing material changes how the at least one oscillating magnet oscillates.

[0030] Preferably, the sensing material is different from the housing component, the connecting body, and / or the at least one oscillating magnet.

[0031] Preferably, the sensing material is different to all three of housing component, connecting body and oscillating magnet. Preferably, the sensing material is different from the housing component.

[0032] In some embodiments, the sensing material may be the same as the housing component or may be different.

[0033] In some embodiments, the sensing material may be the same as the sensing component or may be different.

[0034] Preferably, the excitable device is wireless.

[0035] By being wireless, the excitable device may not be connected to wires, like electric power wires and communication wires.

[0036] Preferably, the excitable device is passive and / or small (for example 4 or 5 mm in diameter and 10 mm in length, or 1 mm in diameter and 3 mm in length).

[0037] By being passive, the device may not require an internal power source to operate and cannot amplify or generate energy, and may only store, dissipate, or redirect energy. By being small, the excitable device occupies minimal volume to enable a broader range of possible applications. Preferably, the housing component is at least partially, preferably completely, surrounded by the sensing material.

[0038] The term "surrounded" may mean that the part surrounding (e.g. the sensing material) is outside of the surrounded part (e.g. the housing component), preferably enclosing it and / or encapsulating it. The surrounding part (e.g. the sensing material) may be located at all sides outside of the surrounded part (e.g. the housing part) - or located at at least a part of at least one side (partially). The surrounding part may be in direct contact with the surrounded part or some other part may be in between.

[0039] Preferably, the at least one oscillating magnet, the connecting body and the sensing material are surrounded by a combination of the housing component and a permeable structure, wherein the permeable structure is permeable to the at least one physical and / or chemical parameter.

[0040] Preferably, the housing component is not permeable to the at least one physical and / or chemical parameter. The housing component may be physically and / or chemically isolating.

[0041] Preferably, the permeable structure is a mesh.

[0042] Preferably, the sensing material is located in a volume defined by the permeable structure.

[0043] Preferably, the at least one oscillating magnet, the connecting body and the sensing material are fully isolated from the surrounding medium by the housing component.

[0044] The term "isolated" may refer to the condition in which a system, component, or substance is chemically and / or physically separated from its surroundings to prevent interaction or interference. The term "isolated" may also or alternatively be referred to as "sealed". Chemical isolation may in some embodiments prevent the diffusion of oxygen (oxygen sealing) or other molecular species. Physical isolation in some embodiments may prevent mechanical contact with the surroundings, for example liquids (e.g. water sealing) or tissue. The at least one oscillating magnet, the connecting body and the sensing material may be fully surrounded by the housing component.

[0045] Preferably, the full isolation is with respect to surrounding solids and liquids. This includes in particular viscoelastic materials and water.

[0046] Preferably, the full isolation is with respect to gases. This includes in particular oxygen.

[0047] Preferably, the connecting body is elongated having a long side longer than any other sides of the connecting body, wherein the at least one oscillating magnet coupled to the one part of the connecting body is coupled to an end of the long side.

[0048] Preferably, another end of the long side is coupled to the housing component.

[0049] Preferably, the connecting body is non-rigid, preferably an elastic component, more preferably a cantilever.

[0050] Preferably, at least one part of the at least one connecting body is coupled to the housing component.

[0051] Preferably, the cantilever is formed like a fork with two or more tips. The fork end may be connected to the housing component. One or more of the fork tips may be connected to the at least one oscillating magnet - preferably one oscillating magnet per fork tip.

[0052] Preferably, the sensing material comprises at least one of: a hydrogel, viscoelastic materials, elastomers, a natural rubber, a silicone rubber, an elastomer foam, a liquid crystal elastomer, a polymerizable monomer, a gel, an oleogel, an organogel, an aerogel, composite gels, a composite structure of hydrogels or rubbers with infused particles, or patterned or combined structures, and a liquid. In alternatives, the sensing material may comprise or be a solid or a liquid. Preferably, the sensing material is a hydrogel.

[0053] Preferably, the connecting body is at least partially surrounded by, preferably embedded in, the sensing material.

[0054] Preferably, the connecting body is in contact with the sensing material.

[0055] Preferably, the housing component and / or the connecting body are insensitive to the at least one physical and / or chemical parameter.

[0056] Preferably, the at least one physical and / or chemical parameter is at least one of: radiation, electric fields, magnetic fields, ultrasound fields, pressure, light, temperature, pH, biomarkers, biochemicals, and glucose, including also biomarker, biochemical, and glucose concentrations. Most preferably, the at least one physical and / or chemical parameter is at least one of: radiation, ultrasound fields, pressure, light, pH, biomarkers, biochemicals, and glucose, including also biomarker, biochemical, and glucose concentrations. In some embodiments the at least one physical and / or chemical parameter is other than temperature.

[0057] Radiation may refer to alpha, beta, gamma, proton, ion, or electromagnetic radiation, preferably gamma-radiation. The radiation may come from an external source (e.g. a linear accelerator) or from a radiation source included on the same device (e.g. for brachytherapy).

[0058] Preferably, the at least one mechanical property is viscosity and / or elasticity, wherein the at least one physical and / or chemical parameter is radiation, and wherein the viscosity and / or the elasticity changes in response to the radiation.

[0059] Preferably, the mechanical property is stiffness. The mechanical property may be represented by relaxation time and / or fracture limit. Preferably, the mechanical property is reversible, such that the sensing material returns to its original state of deformation (i.e. recoverable strain) upon stress and / or deformation exerted by the connecting body during and / or after the oscillation of the connecting body.

[0060] Preferably, the change of the at least one mechanical property of the sensing material changes the resonance frequency and / or damping behavior of the at least one oscillating magnet configured to mechanically oscillate.

[0061] The present disclosure also relates to a system comprising: at least one excitable device as described; an exciting module configured to excite the at least one excitable device causing an oscillation of the at least one oscillating magnet, preferably by generating at least one external force and / or torque; at least one sensing module configured to sense a magnetic field generated by the at least one oscillating magnet of the at least one excitable device, wherein the sensed magnetic field is associated with the change of the at least one mechanical property of at least one sensing material; and a processing module configured to determine at least one physical and / or chemical parameter based on the sensed magnetic field.

[0062] The present disclosure also relates to a method for detecting at least one physical and / or chemical parameter using at least one excitable device as described, the method comprising: providing at least one oscillating magnet configured to mechanically oscillate, preferably at the resonance frequency, upon excitation; providing a housing component; providing a connecting body having one part coupled to the least one oscillating magnet; providing a sensing material configured to change at least one mechanical property in response to the at least one physical and / or chemical parameter, wherein the change of the at least one mechanical property of the sensing material changes how the at least one oscillating magnet is configured to mechanically oscillate; exciting the at least one excitable device causing an oscillation of the at least one oscillating magnet, preferably by generating at least one external force and / or torque; determining the resonance frequency and / or damping behavior of the at least one oscillating magnet configured to mechanically oscillate, preferably by sensing a magnetic field generated by the at least one oscillating magnet of the at least one excitable device; and detecting the at least one physical and / or chemical parameter based on the determination of the resonance frequency and / or damping behavior of the at least one oscillating magnet; wherein the connecting body and the at least one oscillating magnet are isolated, preferably chemically and / or mechanically, from a surrounding medium by the housing component or by a combination of the housing component and the sensing material.

[0063] Regarding "determining the resonance frequency and / or damping behavior of the at least one oscillating magnet configured to mechanically oscillate, preferably by sensing a magnetic field generated by the at least one oscillating magnet of the at least one excitable device", this may also or alternatively happen by sensing an acoustic (being mechanical) signal via vibration. This may be done using a transducer.

[0064] Preferably, the at least one excitable device is a plurality of excitable devices, the method further comprising: detecting a respective at least one physical and / or chemical parameter using a corresponding respective excitable device from the plurality of excitable devices.

[0065] Preferably, the at least one excitable device is a plurality of excitable devices, the method further comprising: detecting a respective at least one physical and / or chemical parameter using each of the plurality of excitable devices. In some embodiments, different information are detected from different excitable devices. For example, temperature is detected from a first excitable device, pH from a second excitable device, and the presence of biomarkers from a third excitable device.

[0066] Preferably, the method further comprising: determining a position and / or orientation of the at least one excitable device, preferably based on a magnetic field generated by the at least one oscillating magnet of the excitable device.

[0067] The present disclosure also relates to an excitable device for obtaining at least one physical and / or chemical parameter, the excitable device comprising: at least one oscillating magnet being configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; and at least one damping component being configured to damp the oscillation of the at least one oscillating magnet for obtaining at least one physical and / or chemical parameter.

[0068] Various embodiments may preferably implement the following features:

[0069] Preferably, the at least one damping component comprises or is at least one electrically conductive material, more preferably allowing Eddy current, induced upon interaction with a varying magnetic field generated by the at least one oscillating magnet, to flow.

[0070] Preferably, the conductivity of the at least one electrically conductive material is equal to or larger than 5 * 106[S / m], more preferably 50 x 106[S / m],

[0071] Preferably, an electrical conductivity of the at least one electrically conductive material is configured to change in response to a change in the at least one physical and / or chemical parameter.

[0072] Preferably, the at least one damping component comprises or is at least one material having a relative magnetic permeability, more preferably around 1, yet more preferably less than 1.

[0073] Preferably, a relative distance and / or orientation between the at least one oscillating magnet and the at least one damping component is configured to change in response to a change in the at least one physical and / or chemical parameter.

[0074] Preferably, at least one portion of the excitable device is deformable, preferably having a bellow structure, upon interaction with the at least one physical and / or chemical parameter.

[0075] Preferably, the excitable device comprises at least one deformable component being configured to deform upon interaction with the at least one physical and / or chemical parameter. Preferably, the excitable device further comprises a connecting body, more preferably a non- rigid body, yet more preferably a cantilever, having one end connected to a part of the excitable device and the other end connected to the at least one oscillating magnet.

[0076] Preferably, the at least one oscillating magnet and / or the connecting body of the excitable device is placed inside a cavity and / or a housing, wherein the cavity and / or a housing isolates the at least one oscillating magnet and / or the connecting body of the excitable device from a direct mechanical contact to a surrounding medium, more preferably wherein the cavity and / or the housing is filled with a gas or vacuum.

[0077] Preferably, the excitable device further comprises a processing module being configured to determine at least one physical and / or chemical parameter based on the damping of the oscillation of the at least one oscillating magnet.

[0078] The present disclosure also relates to a system comprising: an excitable device of any one of the embodiments disclosed herein; an exciting module being configured to excite the excitable device causing an oscillation of the at least one oscillating magnet, preferably by generating at least one external force and / or torque; at least one sensing module being configured to sense a magnetic field generated by the at least one oscillating magnet of the excitable device, wherein the magnetic field is associated with a damping caused by the at least one damping component of the at least one oscillating magnet; and a processing module being configured to determine at least one physical and / or chemical parameter based on the sensed magnetic field.

[0079] The present disclosure further relates to a method for obtaining at least one physical and / or chemical parameter using the excitable device of any one of the embodiments disclosed herein, the method comprising: providing at least one oscillating magnet being configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; and providing at least one damping component being configured to damp the oscillation of the at least one oscillating magnet for obtaining at least one physical and / or chemical parameter. Preferably, the method further comprises exciting the excitable device causing an oscillation of the at least one oscillating magnet, more preferably by generating at least one external force and / or torque.

[0080] Preferably, the method further comprises sensing a magnetic field generated by the at least one oscillating magnet of the excitable device, wherein the magnetic field is preferably associated with a damping caused by the at least one damping component of the excitable device.

[0081] Preferably, the method further comprises determining the at least one physical and / or chemical parameter based on the sensed magnetic field.

[0082] Preferably, the at least one physical parameter and the at least one chemical parameter are obtainable and / or obtained from a single set of sensed magnetic field.

[0083] Preferably, the damping parameter 6 is tunable and / or tuned independently from the resonance frequency fres.

[0084] Preferably, the at least one damping component comprises a conductive material, wherein the conductive material comprises or is at least one of a Neodymium magnet (NdFeB), an Aluminum, and a Copper.

[0085] Preferably, the excitable device is a magneto-oscillatory device.

[0086] Preferably, the excitable device comprises or is a housing.

[0087] Preferably, the housing comprises, more preferably physically contains, the at least one oscillating magnet the cantilever and the one end of the connecting body is connected to a part of the housing. Preferably, the housing comprises, more preferably physically contains, the at least one clamping component and is magnetically coupled to the at least one oscillating magnet.

[0088] Preferably, the at least one damping component is part of the housing and is magnetically coupled to the at least one oscillating magnet.

[0089] Preferably, the at least one damping component is placed outside the housing and is magnetically coupled to the at least one oscillating magnet.

[0090] Preferably, the housing is water-tight.

[0091] Preferably, the housing is rigid, wherein rigid being the structural deformation percentage of the housing below 1%, even more preferably below 0.1 %, ideally 0 %.

[0092] Preferably, the excitable device comprises a further penetrable housing, more preferably a mesh.

[0093] Preferably, the penetrable housing comprises at least one deformable component, more preferably a gel, wherein the deformable component is configured to deform in response to an interaction with at least one physical and / or chemical component.

[0094] Preferably, the at least one physical and / or chemical component penetrates through the further penetrable housing.

[0095] Preferably, the penetrable housing further comprises the at least one damping component, wherein the at least one deformable component, upon deformation in response to an interaction with at least one physical and / or chemical component, is configured to change a location and / or orientation of the at least one damping component with respect to the at least one oscillating magnet. The present disclosure further relates an excitable device for obtaining at least one physical and / or chemical parameter, the excitable device comprising: at least one magnetic component being configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; at least one elastic component being coupled to the least one magnetic component; at least one housing component being configured to isolate, preferably chemically and / or physically, the at least one elastic component and the at least one magnetic component from a surrounding medium; and at least one sensing component being configured to modify the oscillation of the at least one magnetic component.

[0096] Preferably, the at least one sensing component comprises or is at least one electrically conductive material allowing Eddy current to flow, wherein the Eddy current is induced upon interaction with a varying magnetic field generated by the at least one magnetic component.

[0097] Preferably, an electrical conductivity of the at least one electrically conductive material is configured to change in response to a change in the at least one physical and / or chemical parameter.

[0098] Preferably, the at least one sensing component is in contact with and / or coupled to the at least one elastic component and / or with the at least one magnetic component, preferably for inducing a change of damping and / or frequency upon change of at least one physical and / or chemical property of the at least one sensing component.

[0099] Preferably, a contact area between the at least one elastic component and the at least one sensing component is configured to change in response to a change in the at least one physical and / or chemical parameter.

[0100] Preferably, at least one mechanical property of the at least one sensing component is configured to change in response to a change in the at least one physical and / or chemical parameter, preferably, the at least one mechanical property is a viscosity and / or an elasticity. Preferably, the at least one sensing component comprises or is at least one material having a relative magnetic permeability, preferably around 1, more preferably less than 1.

[0101] Preferably, a relative distance and / or orientation between the at least one magnetic component and the at least one sensing component is configured to change in response to a change in the at least one physical and / or chemical parameter.

[0102] Preferably, at least one portion of the excitable device is deformable, preferably having a bellow structure, upon interaction with the at least one physical and / or chemical parameter.

[0103] Preferably, the at least one sensing component comprises or is at least one deformable component being configured to deform upon interaction with the at least one physical and / or chemical parameter, preferably the at least one deformable component is a hydrogel and the at least one chemical parameter is a pH level of the surrounding medium.

[0104] Preferably, the excitable device further comprises a processing module being configured to determine at least one physical and / or chemical parameter based on the sensing of the oscillation of the at least one magnetic component.

[0105] The present disclosure further relates to a system comprising: at least one excitable device as described; an exciting module being configured to excite the at least one excitable device causing an oscillation of the at least one oscillating magnet, preferably by generating at least one external force and / or torque; at least one sensing module being configured to sense a magnetic field generated by the at least one oscillating magnet of the at least one excitable device, wherein the magnetic field is associated with a modified oscillation caused by the at least one sensing component of the at least one magnetic component; and a processing module being configured to determine at least one physical and / or chemical parameter based on the sensed magnetic field.

[0106] The present disclosure further relates to a method for obtaining at least one physical and / or chemical parameter using at least one excitable device as described, the method comprising: providing at least one magnetic component being configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; providing at least one elastic component being coupled to the least one magnetic component; providing at least one housing component being configured to isolate, preferably chemically and / or physically, the at least one elastic component and the at least one magnetic component from a surrounding medium; and providing at least one sensing component being configured to modify the oscillation of the at least one magnetic component.

[0107] Preferably, the method further comprises exciting the at least one excitable device causing an oscillation of the at least one magnetic component, preferably by generating at least one external force and / or torque.

[0108] Preferably, the method further comprises sensing a magnetic field generated by the at least one magnetic component of the at least one excitable device, wherein the magnetic field is preferably associated with a modified oscillation caused by the at least one sensing component of the at least one excitable device.

[0109] Preferably, the method further comprises determining the at least one physical and / or chemical parameter based on the sensed magnetic field.

[0110] Preferably, the method further comprises determining a location of the at least one excitable device based on a magnetic field generated by the at least one magnetic component of the excitable device.

[0111] Preferably, the at least one excitable device is a plurality of excitable devices, the method further comprising: obtaining a respective at least one physical and / or chemical parameter of a corresponding respective excitable device of the plurality of excitable devices based on a magnetic field generated by the at least one magnetic component of the corresponding respective excitable device; and / or determining a respective location of a corresponding respective excitable device of the plurality of excitable devices based on the magnetic field generated by the at least one magnetic component of the corresponding respective excitable device.

[0112] Herein, a magnetic component may comprise or be an oscillating magnet, a sensing component may comprise or be a damping component, and a modification of an oscillation may comprise or be a damping of an oscillation.

[0113] Examples, alternatives, advantages and other explanations for some of these aspects are explained at other parts of this disclosure.

[0114] The described advantages of the aspects are neither limiting nor exclusive to the respective aspects. An aspect might have more advantages, not explicitly mentioned.

[0115] The exemplary embodiments disclosed herein are directed to providing features that will become readily apparent by reference to the following description when taken in conjunction with the accompany drawings. In accordance with various embodiments, exemplary systems, methods, devices and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of the present disclosure.

[0116] The above and other aspects and their implementations are described in greater detail in the drawings, the descriptions, and the claims.

[0117] Description of the Drawings

[0118] FIG. 1 illustrates components of a magneto-oscillatory device.

[0119] FIG. 2 illustrates components of a magneto-oscillatory device. FIG. 3 illustrates a flow chart of a method for obtaining at least one physical and / or chemical parameter using the excitable device of some of the embodiments disclosed herein.

[0120] FIG. 4 illustrates the components comprised in an excitable device according to an embodiment of the present disclosure.

[0121] FIG. 5 a) illustrates components of an excitable device according to an embodiment of the present disclosure.

[0122] FIG. 5 b) illustrates components of an excitable device according to an embodiment of the present disclosure.

[0123] FIG. 6 a) illustrates an excitable device according to an embodiment of the present disclosure.

[0124] FIG. 6 b) illustrates the damping coefficient and the resonance frequency for various conductive materials according to an embodiment of the present disclosure.

[0125] FIG. 7 illustrates an excitable device according to an embodiment of the present disclosure.

[0126] FIG. 8 a) illustrates experimental results obtained using the system comprising an excitable device according to an embodiment of the present disclosure.

[0127] FIG. 8 b) illustrates experimental results obtained using the system comprising an excitable device according to an embodiment of the present disclosure.

[0128] FIG. 9 illustrates an excitable device according to an embodiment of the present disclosure.

[0129] FIG. 10 a) illustrates experimental results obtained using the system comprising an excitable device according to an embodiment of the present disclosure. FIG. 10 b) illustrates experimental results obtained using the system comprising an excitable device according to an embodiment of the present disclosure.

[0130] FIG. 11 a) illustrates an excitable device according to an embodiment of the present disclosure.

[0131] FIG. 11 b) illustrates a system according to an embodiment of the present disclosure.

[0132] Fig. 12 illustrates a flow chart of a method for obtaining at least one physical and / or chemical parameter using the excitable device of some of the embodiments.

[0133] FIG. 13 illustrates an excitable device according to an embodiment of the present disclosure.

[0134] Figs. 14 a) and 14 b) show a measurement of frequency over time by incremental application of radiation.

[0135] FIG. 15 illustrates an excitable device according to an embodiment of the present disclosure.

[0136] FIG. 16 illustrates an excitable device according to an embodiment of the present disclosure.

[0137] FIG. 17 illustrates an excitable device according to an embodiment of the present disclosure.

[0138] In the following, exemplary embodiments of the disclosure will be described. It is noted that some aspects of any one of the described embodiments may also be found in some other embodiments unless otherwise stated or obvious. However, for increased intelligibility, each aspect will only be described in detail when first mentioned and any repeated description of the same aspect will be omitted.

[0139] FIG. 3 illustrates a flow chart of a method for obtaining at least one physical and / or chemical parameter using the excitable device of some of the embodiments, especially embodiments 1 to 3, disclosed herein. The method comprises: in S301, providing at least one oscillating magnet being configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; and in S302, providing at least one damping component being configured to damp the oscillation of the at least one oscillating magnet for obtaining at least one physical and / or chemical parameter, wherein the at least one damping component comprises or is at least one electrically conductive material being configured to damp the oscillation by allowing Eddy current to flow in the at least one electrically conductive material, and wherein the Eddy current is induced upon interaction with a varying magnetic field generated by the at least one oscillating magnet.

[0140] In an embodiment, the method further comprises determining the at least one physical and / or chemical parameter based on the sensed magnetic field.

[0141] In an embodiment, the excitable device, used to perform the method of FIG. 3, for obtaining at least one physical and / or chemical parameter comprises: at least one oscillating magnet being configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; and at least one damping component being configured to damp the oscillation of the at least one oscillating magnet for obtaining at least one physical and / or chemical parameter, wherein the at least one damping component comprises or is at least one electrically conductive material being configured to damp the oscillation by allowing Eddy current to flow in the at least one electrically conductive material, and wherein the Eddy current is induced upon interaction with a varying magnetic field generated by the at least one oscillating magnet.

[0142] The following further discusses an excitable device according to an embodiment of the present disclosure, in particular regarding the magneto-oscillatory devices, more particularly the characteristics, the parameters involved, and the utilization thereof.

[0143] Oscillation parameters of an excitable device according to an embodiment of the present disclosure:

[0144] The following assumes the excitable device comprising the components and the structure as shown in FIG. 1. The resonance frequency fresof the system relates to the clamping according to: wherein 6 denotes a damping coefficient. This parameter corresponds to the dissipation of the system's energy into the environment. The higher the damping, the faster the oscillation amplitude 0(t) decays and comes to a stop. All mechanical systems exhibit damping to varying degrees, and in a cantilever-mass system the main energy-losses are due to internal material friction, air friction, and mechanical coupling of the fixed cantilever end. Further, it will be illustrated in various embodiments that an additional damping component, in particular a conductive material inducing eddy current therein upon magnetic interaction with the oscillating magnet, can be used for sensing applications. In some embodiments, the additional damping component is due to a sensing material with a changing mechanical property in response to the at least one physical and / or chemical parameter. This can be used for sensing applications.

[0145] "Contactless" modification of oscillation parameters:

[0146] Parameter 6 of the magneto-oscillatory system can also be modified with a complete reversibility without a mechanical contact to the system. The damping coefficient 6 can be modified by applying or placing a conductive material in proximity to the oscillating permanent magnet. In FIG. 4, the damping component is a conductive material 440 and is placed at a distance d away from the permanent magnet 430 at its stationary position, in the direction opposite to a fixed point, where the cantilever 420 is mechanically fixed to the object 410. Accordingly, a relative motion between the magnetic field of the oscillating magnet 430 and the conductive material 440 induces electrical currents into the conductive material 440, called eddy currents. These currents flow in a circular path within the material 440, such that they generate a magnetic field themselves. This generated magnetic field always opposes the moving magnetic field generated by the permanent magnet 430. Due to the interaction of these magnetic fields, the permanent magnet 430 experiences a drag force contrary to its moving direction, leading to the damping of the oscillation. As such, it is understood by the skilled person that the placement and / or orientation of the conductive material 440 as shown in FIG. 4 is non-limiting and can be modified, particularly as long as such placement yields the aforementioned damping of the motion of the oscillating permanent magnet 430. The energy is dissipated in this process purely as heat by the electrons flowing against an electrical resistance inside the conductive material 440. The amount of damping is related to the distance d between the permanent magnet 430 and the conductive material 440. It is estimated that 6 scales with d3.

[0147] The structural configuration and the physical characteristics of the object or ground 410, cantilever 420, and the magnet 430 in FIG. 4 may be the same as those of the respective object or ground 110, cantilever 120, and the magnet 130 in FIG. 1.

[0148] In an embodiment, a change of the resonance frequency fresis less than a change of the damping parameter s, preferably when 2 f0» 3.

[0149] Functionalization of the parameters:

[0150] Both damping parameter 6 and the resonance frequency frescan be functionalized by the distance d between the permanent magnet 430 and the conductive material 440 in a housing, e.g., either comprising deformable portion or a portion of said housing is deformable, which is sensitive to an external parameter, e.g., physical and / or chemical parameter.

[0151] The internal material properties of the conductive material can also be functionalized to avoid physical deformation. The conductive material with a high electrical conductivity, e.g., 5*106[S / m], more preferably 50xl06[S / m], may be preferred to obtain a noticeable damping effect. Materials exist that show conductivity dependence on various external parameters like temperature, chemicals, pH, and more. In an embodiment, the volume and density of the conductive material is very high to allow strong eddy currents. The volume and density of the conductive material should be maximized for the desired design and / or application. While materials with open porosity have a higher surface area than the bulk material for improved interaction with surrounding liquids or gases, said open porous materials have a lower density of the conductive material in the same volume. This implies weaker eddy currents for open porous structures. In one embodiment, the density and volume of the conductive material is optimized to provide sufficient eddy currents while providing sufficient surface area to interact with surrounding liquids or gases.

[0152] The damping component, e.g., as implemented with a single conductive material 440 in FIG. 4, may comprise a plurality of conductive materials. Specifically, the damping component may form a transistor-like structure, yielding a transistor-like conductive material 510 as shown in FIG. 5 a). For instance, the two conductive materials 511 and 513 may electrically connect and conduct the electricity based on the change in the conductivity within the region (i.e., a conductivity-changing sub-component in this embodiment) 512 in response to or depending on external parameters. The principle can be compared to electrical transistors, where, for example, photodiodes have a light-sensitive sub-component which acts as a conductor or an insulator depending on the light reception. FIG. 5 b) illustrates an equivalent diagram of the transistor-like conductive material 510 shown in FIG. 5 a). That is, 520, 521, 522, and 523 represent 510, 511, 512, and 513, respectively. It is understood by the skilled person that the structural and / or electrical characteristics of the transistor-like conductive material 510 is non-limiting and can be modified, particularly when said material yields the aforementioned damping effect of the oscillating permanent magnet 430. The damping component may be a transistor. The conductivity of said transistor may be controlled, in particular using an external signal.

[0153] The damping component may comprise at least one material having a relative magnetic permeability pr. For a material with a relative magnetic permeability, i.e., e.g., pr~ 1, the magnetic fields easily penetrate said material and said material does not become magnetized. For a material with pr> 1, i.e., e.g., ferromagnetic materials such as iron (pr~ 5000) or neodymium (pr~ 1.05), the material becomes magnetized when exposed to a magnetic field, which results in a magnetic field interaction with the resonator to induce a frequency shift. Thus, a material with the relative magnetic permeability pr~ 1 and / or with a high electrical conductivity, e.g., 5*106[S / m], more preferably 50xl06[S / m], may be preferred. In an embodiment, said material is a diamagnetic material, preferably any one of a copper and silver, or a paramagnetic material, preferably aluminum.

[0154] The functionalization as disclosed above and the embodiments disclosed herein may advantageously achieve, among others, the following. Tuning of the resonance frequency may improve a sensitivity, i.e., achieve a high sensitivity, over a wide range of displacements d. Tuning of the damping coefficient may achieve: a very high sensitivity in close proximity, a system with low sensitivity to the external tools as the conductive material has to be very close to the excitable device to disturb the damping, material internal properties can be changed more easily to avoid the displacement-based method, and / or very little forces act on the damping component, thereby simplifying the design requirements.

[0155] The following illustrates non-limiting embodiments of an excitable device, a method using said excitable device, and a system comprising said excitable device according to any one of the embodiments of the present disclosure.

[0156] Embodiment 1:

[0157] In reference to FIG. 6 a), in an embodiment, an excitable device 600 is used for obtaining a conductivity and / or thickness of a conductive material 640. The excitable device 600 comprises: an oscillating magnet 630 being configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; and a conductive material 640 being configured to damp the oscillation of the oscillating magnet 630 for obtaining the conductivity and / or thickness of the conductive material 640. The conductive material 640 is placed at a distance d away from the oscillating magnet 630 in a similar manner as illustrated in FIG. 4. Further, the excitable device 600 comprises a cantilever 620 having one end being connected to one wall of a housing 610 of the excitable device 600 and the other end being connected to the oscillating magnet 630. The excitable device 600 may comprise the housing 610 for facilitating, i.e., comprising, in particular, within the physical space therein, the oscillating magnet 630 and the cantilever, and optionally the conductive material 640. The housing 610 may isolate the components therein from any physical and / or chemical component surrounding the housing 610. The housing 610 may be rigid and maintain its form upon interaction with the physical and / or chemical component surrounding the housing 610. It is understood by the skilled person that the conductive material 640 may be placed inside or outside the housing 610 and / or in any orientation, particularly as long as the conductive material 640 causes the aforementioned damping effect on the oscillating magnet 630. The excitable device 600 may be the housing 610. The conductive material 640 may be part of the housing 610.

[0158] In an embodiment, the excitable device 600 is magnetically excited, e.g., using an exciting module, and the damping of the magnetic field generated by the magnetically excited excitable device 600 can be measured, e.g., by one or more sensing module(s), preferably located external to the excitable device. The measured magnetic field may be converted into the damping coefficient 6, e.g., according to the relations in eq. (1) to (4). Such conversion may be performed by a processing module (not shown). FIG. 6 b) illustrates the obtained damping coefficient 6 [1 / s] on the y-axis on the left of FIG. 6 b) and the obtained resonance frequency fres[Hz] of the oscillating magnet 630 on the y-axis on the right of FIG. 6 b). The x- axis of FIG. 6 b) illustrates the various conductive materials 640 used: no conductive material plate (reference), a plate of polymethyl methacrylate (PMMA) having thickness of 800 pm, a plate of Aluminum (Al) having thickness of 80 pm, a plate of copper (Cu) having thickness of 300 pm, and a plate of copper (Cu) having thickness of 500 pm, in the order of 641-1 to 645- 1 (resonance frequency, indicated by circles) and 641-2 to 645-2 (damping, indicated by crosses).

[0159] Without a material plate (Reference), the damping is around 2 [1 / s] (i.e., data point 641-2). For a non-conductive PMMA (i.e., the material having the conductively of approximately 10“19[S / m]) plate, a similar damping value (i.e., data point 642-2) as the reference, i.e., no material plate, is observed. This is because no eddy current is induced, hence no measurable or significant damping, i.e., which is caused by the conductive plate, occurs. For conductive plates of aluminum and copper (one with thickness of 300 pm another with thickness of 500 pm), the damping increases drastically by several factors (see data points 643-2 to 645-2, respectively). Meanwhile, the resonance frequencies 641-1 to 645-1 (circles) stay nearly the same and show only a small statistical variance due to the repeated fixation of the sensor and plate. This leads to the conclusion that eddy current damping generates a clearly measurable effect. Material thickness and conductivity influence the magnitudes of damping. Hence, this approach could be used to obtain the material thickness, conductivity, or indirectly other material properties over the conductivity (e.g. grain size, defects, fractures, composition, temperature, ...). It is understood by the skilled person that the materials of the conductive material 640 presented herein are non-limiting and any material may be used, in particular, when said material changes conductivity by chemical or physical interaction.

[0160] Embodiment 2:

[0161] In reference to FIG. 7, in an embodiment, an excitable device 700 is used for obtaining displacement and / or force. The excitable device 700 comprises: an oscillating magnet 730 being configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; and a conductive material 740 being configured to damp the oscillation of the oscillating magnet 730 for obtaining displacement and / or force. The excitable device 700 further comprises a housing 710. The physical configuration of the excitable device 600 in FIG. 6 applies to the excitable device 700 in FIG. 7, except for that the housing 710 is deformable, e.g., by having a bellow structure as chosen for this non-limiting embodiment, when displacement force, or pressure (not shown), is exerted onto the housing 710 as indicated by the arrow in FIG. 7. Said displacement force, or pressure, alters the relative distance d between the oscillating magnet 730 and the conductive material 740.

[0162] In the embodiment, the excitable device 700 is magnetically excited, the magnetic field generated by said oscillating magnet 730 is measured, and the damping effect is obtained, in the manner described for the excitable device 600. The conductive material 740 is chosen to be a copper plate having thickness of 300 pm and the damping coefficient 6 [1 / s] (left y-axes on FIG. 8 a) and FIG. 8 b), cross symbols) and resonance frequency fres[Hz] of the oscillating magnet 630 (right y-axes on FIG. 8 a) and FIG. 8 b), circle symbols) is obtained for various relative displacement Ad [pm] (x-axes on FIG. 8 a) and FIG. 8 b)). The relative displacement measures the difference in the position of the conductive material 740 with respect to a reference, i.e., stationary position. The distance between the oscillating magnet 730 and the conductive material 740 after the displacement is d' = d + Ad. In reference to FIG. 8 a), it is observed that the damping increases as the absolute value of Ad increases, i.e., as the oscillating magnet 730 gets closer to the conductive material 740. The sensitivity to deformation also increases for smaller distances, as the damping response is strongly nonlinear. In reference to FIG. 8 b), much smaller increments of displacements in the sub-um range are applied, and the damping effect arising therefrom is still observable. Accordingly, the relative displacement can be obtained.

[0163] Furthermore, by measuring the elastic modulus of the deformable housing 710, the displacement can be related to an applied force. In the embodiment, the housing 710 had an elastic modulus of 363 N / m, meaning that 1 pm of deformation corresponds to 0.363 mN of force. In the data range shown in FIG. 8 a) and FIG. 8 b), the relation between damping and force is approximately 0.1 1 / s per 0.4 mN or 0.25 l / (s*mN). The force sensitivity is directly related to the housing's elastic modulus; hence, it can be tuned by using different housing materials and / or designs.

[0164] Embodiment 2 is particularly beneficial where typical wired force sensors are undesired, e.g. surgical device feedback, robotic applications, blood pressure sensors, and others.

[0165] Embodiment 3:

[0166] In reference to FIG. 9, in an embodiment, an excitable device 900 is used for obtaining pH level of a liquid, preferably a solution, and more preferably an aqueous solution. The excitable device 900 comprises an oscillating magnet 930 being configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; and a conductive material 940 being configured to damp the oscillation of the oscillating magnet 930 for obtaining pH level of a liquid, preferably a solution, and more preferably an aqueous solution. The excitable device 900 further comprises a pH-responsive hydrogel 950, i.e., a deformable component. In this case, Glutaraldehyde-crosslinked chitosan is used as the hydrogel 950. The excitable device 900 further comprises a mesh 960, e.g., a hollow cylinder of nylon mesh. The mesh 960 is mechanically coupled to the housing 910. The mesh 960 has at least two functions: it constrains the expansion of the hydrogel to one direction, i.e., towards the oscillating magnet 940, while still allowing fast diffusion through its pores, i.e., allows the liquid surrounding the excitable device to penetrate therethrough and enable the contact between the liquid and the pH-responsive hydrogel 950. In response, the volume of the pH-responsive hydrogel 950 either increases or decreases, which in turn displaces the conductive material 940. This causes the changes in the distance d or orientation (not shown) between the conductive material 940 and the oscillating magnet 930. The conductive material 940 may be adhered to the hydrogel 950 using adhesives or surface functionalization of one, or both, surfaces. In this embodiment, the housing 910, which comprises the cantilever 920 and the oscillating magnet 930, is watertight, so as to prevent the liquid surrounding the excitable device 900 from penetrating, thereby preventing the liquid from directly impacting the damping coefficient. It is understood by the skilled person that the embodiment of FIG. 9 is non-limiting and can be modified, particularly so long that the chemical interaction between a chemical component and a deformable component changes a physical and relative placement and / or orientation between the oscillating magnet 930 and the conductive material 940. In general, a housing may be configured to isolate the components therein from a direct mechanical contact with a surrounding medium. For instance, the housing 910 isolates the cantilever 920 and the oscillating magnet 930 from a direct mechanical contact with a surrounding medium.

[0167] In the embodiment, the excitable device 900 is magnetically excited, the magnetic field generated by said oscillating magnet 930 is measured, and the damping effect is obtained, in the manner described for the excitable device 600. A copper plate is chosen for the conductive material 940. The obtained damping coefficient 6 [1 / s] on the y-axis on the left of FIG. 10 a) and FIG. 10 b) are plotted (solid lines) with respect to time [min] on the x-axis of said figures. The y-axis on the right of FIG. 10 a) (dashed line) denotes a relative displacement Ad [mm]. In reference to FIG. 10 a), the data points 1001 represent 6 and the data points 1002 represent Ad. When the excitable device 900 is placed in pH 4 buffer solution (i.e., t = 0 to 35 min), the hydrogel does not respond and small to no difference, i.e., negligible variation, in damping is obtained. After immersing the excitable device 900 into pH 7 double-distilled water (i.e., t = 35 to 130 min), the hydrogel 950 swells, pushing the copper plate closer to the oscillating magnet 940 (as shown by the data points 1002), which leads to an increase of damping (as shown by the data points 1001). After re-immersing the excitable device 900 into pH 4 solution (i.e., t = 130 to 205 min), the hydrogel 950 shrinks again. The complete reversibility of this process is shown in FIG. 10 b) for three pH-changing cycles.

[0168] It is noted that it may be important to minimize the minimal distance d which can be achieved, as it increases the sensitivity.

[0169] It should be noted, that such a design cannot be achieved by replacing the conductive material with a permanent magnet for frequency-dependent sensing, as the permanent magnet would be attracted by or repulsed from the oscillating magnet, altering the distance d, or orientation, and furthermore leading to a detachment or compression of the hydrogel.

[0170] Embodiment 3 demonstrates a correlation between damping and displacement of the copper plate, as well as the full reversibility in the obtained damping coefficient based on the liquid.

[0171] In an embodiment, an elastic component is placed between the conductive material 940 and the hydrogel 950. This achieves, among others, a better retraction of the conductive material when the hydrogel 950 shrinks after being swollen.

[0172] In an embodiment, the chemical component, of which the property is obtained using the excitable device 900, is or comprises at least one of a liquid, solution, biomarkers, genes such as glucose (blood sugar), tumor / tissue acidity, and antibodies.

[0173] FIG. 11 a) illustrates an excitable device according to an embodiment of the present disclosure. The excitable device 1110 is for obtaining at least one physical and / or chemical parameter, wherein the excitable device 1110 comprises: at least one oscillating magnet 1120 being configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; and at least one damping component 1130 being configured to damp the oscillation of the at least one oscillating magnet for obtaining at least one physical and / or chemical parameter. FIG. 11 b) illustrates a system according to an embodiment of the present disclosure. The system 1100 comprises: an excitable device 1110 of any one of the embodiments disclosed herein; an exciting module 1140 being configured to excite the excitable device causing an oscillation of the at least one oscillating magnet, preferably by generating at least one external force and / or torque; at least one sensing module 1150 being configured to sense a magnetic field generated by the at least one oscillating magnet of the excitable device, wherein the magnetic field is associated with a damping caused by the at least one damping component of the at least one oscillating magnet or the damping caused by the sensing material; and a processing module 1160 being configured to determine at least one physical and / or chemical parameter based on the sensed magnetic field.

[0174] In an embodiment, the magnetic field generated by the at least one oscillating magnet is measured wirelessly by the at least one sensing module, preferably over a long range, more preferably over a range exceeding 10 cm

[0175] In an embodiment, the excitable device has a volume of less than 10 mm3.

[0176] In an embodiment, the excitable device comprises a housing.

[0177] In an embodiment, the housing comprises the at least one oscillating magnet.

[0178] In an embodiment, the housing comprises the at least one damping component.

[0179] In an embodiment, the housing does not comprise the at least one damping component, preferably, the at least one damping component is exposed outside of the housing and / or is exposed to the environment.

[0180] In an embodiment, the excitable device is for obtaining the temperature. The temperature causes the changes in the material's mechanical properties and the magnetic fields due to aforementioned magnetic coupling without any damping component. In an embodiment, the at least one physical parameter and the at least one chemical parameter are obtained from a single set of sensed magnetic field. For instance, both the damping parameter 6 and the resonance frequency fresmay be utilized for obtaining the at least one physical parameter (e.g., pressure) and the at least one chemical parameter (e.g., pH level) simultaneously from a single set of data measured from a single experiment for monitoring both pressure and pH level without having to perform two separate experiments for monitoring the pressure and the pH level separately.

[0181] In an embodiment, the at least one damping component comprises a conductive material, preferably a Neodymium magnet (NdFeB) permanent magnet. NdFeB has conductivity in orders of magnitude lower (0.67*106S / m) in comparison to copper (58*106S / m) and other metals. NdFeB, exhibits pr= 1.05 (ferromagnetic), and additional, it exhibits a high magnetic remanence magnetization (B_r > 1 T) and a high magnetic field coercivity (resistance to demagnetization) (H_c > 500 kA / m).

[0182] The eddy current strength may be dependent on the velocity and therefore the frequency of the oscillating magnet, i.e. higher resonance frequencies (e.g. > 500 Hz) may increase the efficiency of the damping effect caused by the eddy current, according to the embodiments disclosed herein, even more. Further, the eddy current strength may be dependent on the distance.

[0183] The excitable device may be downscaled using various techniques including MEMS fabrication technique, which may further improve the precision, thereby leading to very precision wireless sensing applications.

[0184] FIG. 12 illustrates a flow chart of a method for obtaining at least one physical and / or chemical parameter using the excitable device of some of the embodiments, especially embodiments 4 to 7, disclosed herein. The method comprises: in S1201, providing at least one oscillating magnet configured to mechanically oscillate, preferably at the resonance frequency, upon excitation; in S1202, providing a connecting body having one part coupled to the least one oscillating magnet; in S1203, providing a housing component; and in S1204, providing a sensing material configured to change at least one mechanical property in response to the at least one physical and / or chemical parameter, wherein the change of the at least one mechanical property of the sensing material changes how the at least one oscillating magnet is configured to mechanically oscillate.

[0185] In an embodiment, the method may further comprise: in step 1205, exciting the at least one excitable device causing an oscillation of the at least one oscillating magnet, preferably by generating at least one external force and / or torque; in S1206, determining the resonance frequency and / or damping behaviour of the at least one oscillating magnet configured to mechanically oscillate, preferably by sensing a magnetic field generated by the at least one oscillating magnet of the at least one excitable device; and in S1207, detecting the at least one physical and / or chemical parameter based on the determination of the resonance frequency and / or damping behaviour of the at least one oscillating magnet; wherein the connecting body and the at least one oscillating magnet are isolated, preferably chemically and / or mechanically, from a surrounding medium by the housing component or by a combination of the housing component and the sensing material.

[0186] Embodiments of this disclosure utilize a magneto-oscillatory device of which the housing protects the oscillating components from the surrounding medium and an additional sensing material is modifying the oscillation upon change of a parameter. The overall device comprises an oscillating magnet, an elastic connecting body, a protective housing component and a sensing material. Neither the magnet, nor connecting body, nor the housing component may be configured to sense the desired physical and / or chemical parameter, and the mechanically oscillating components are preferably not exposed to the environment to ensure no significant changes in the oscillation amplitude. The sensing material, however, is in (direct or indirect) contact with the connecting body and / or the magnet such that it modifies the resonance frequency or damping of the oscillation upon change of the desired physical and / or chemical parameter. This can happen, for example, over changes of the elasticity or viscosity (mechanical property) of a hydrogel as sensing material which is situated on the cantilever (connecting body). The sensing material can be in contact with the surrounding medium (environment) to sense parameters, or be fully isolated within the housing. The latter design enables sensing of physical and / or chemical parameters which penetrate the housing component or at least the permeable structure, without affecting its mechanical stability, for example radiation. In practice, such a design enables a robust, wireless sensor which can be miniaturized to several mm3-scale size, can be read out in real-time and operated at large distances above 10 cm.

[0187] Embodiment 4:

[0188] With reference to FIG. 13, in an embodiment, an excitable device 1300 is used for detecting at least one physical and / or chemical parameter. The excitable device 1300 comprising: at least one oscillating magnet 1330 configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; a connecting body 1320 having one part coupled to the at least one oscillating magnet 1330; a housing component 1310; and a sensing material 1370 configured to change at least one mechanical property in response to the at least one physical and / or chemical parameter; wherein the excitable device 1300 is configured such that a change of the at least one mechanical property of the sensing material 1370 changes how the at least one oscillating magnet 1330 oscillates; and wherein the connecting body 1320 and the at least one oscillating magnet 1330 are isolated, preferably chemically and / or mechanically, from a surrounding medium by the housing component 1310.

[0189] The housing component 1310 isolates the oscillating components (oscillating magnet 1330 and connecting body 1320) from direct contact with the environment. A change in oscillation parameters is done over a separate sensing material 1370 which is in contact with the connecting body 1320. The connecting body 1320 does not have to be in direct contact with the housing component 1310 (see also embodiment of fig. 16). Neither the housing component 1310, nor the connecting body 1320 are sensitive to desired physical and / or chemical parameter. This design may be useful to measure interpenetrating physical parameters, e.g electromagnetic radiation, ion beams, proton beams or electric fields, because the nearby environment does not affect the oscillation in any way. The connecting body 1320 may be elastic. The housing may be permeable to the physical and / or chemical parameter, but the physical and / or chemical parameter preferably does not influence the oscillation when the sensing material is not present.

[0190] In an embodiment, the excitable device 1300 is magnetically excited, e.g., using an exciting module, and the frequency and / or the damping of the magnetic field generated by the magnetically excited excitable device 1300 can be measured, e.g., by one or more sensing module(s), preferably located external to the excitable device. The measured magnetic field may be converted into the frequency f and / or the damping coefficient 6, e.g., according to the relations in eq. (1) to (4). Such conversion may be performed by a processing module (not shown).

[0191] In one embodiment, the excitable device 1300 is capable of wirelessly measuring gammaradiation. This may be done by using the setup of fig. 13 and making the sensing material 1370 sensitive to gamma-radiation. As sensing material, a viscoelastic hydrogel containing a radiation-responsive monomer may be used. Upon radiation, free radicals are produced within the hydrogel which lead to radical polymerization of the unpolymerized monomers. This radiation curing process changes the elasticity and / or viscosity of the hydrogel, and thus the frequency and damping are changed. Once the radiation exposure is stopped or interrupted, the polymerization may continue for a short duration until all free radicals are consumed. Similarly, upon starting the radiation exposure, a small temporal delay may occur until the mechanical change of the hydrogel affects the oscillator. A hydrogel which changes its mechanical properties may be referred to as stiffening or softening sensing material, particularly stiffening or softening hydrogel.

[0192] Figs. 14 a) and 14 b) show a measurement of frequency over time by incremental application of radiation. Fig. 14 a) shows the (sum of the) true current radiation dose in the dashed line, the measured resonance frequency in the dots and circles, wherein the dots show when the radiation beam is off and the circles show when the radiation beam is on. Fig. 14 b) shows the change of measured resonance frequency. Again, the dots show when the radiation beam is off and the circles show when the radiation beam is on. After a short duration after starting the measurement, the resonance frequency is constant. Then, 5 Gy of radiation dose are applied, indicated by the slope of the dashed line. After a short duration, the polymerization starts and the resonance frequency increases (circles). After stopping the radiation, the frequency saturates after a short duration. Subsequent applications of 2 Gy, 1 Gy, and 1 Gy each produce prominent changes of the frequency. For reference, typical radiation doses for fractional cancer radiotherapy are above 1.8 Gy per sitting.

[0193] In examples, acrylamide and N, N'-methylenebisacrylamide can be used as monomers, and the concentrations thereof change the radiation dose sensitivity and range. Since they may be liquid in aqueous solution, they can be pre-cured to a point where the gelation starts and sufficient monomers are left within the hydrogel. At the point of gelation, the viscosity and elasticity of the solution increases sharply, dramatically decreasing the damping to gain a stronger magnetic signal. From this point onwards, more radiation dosage continues to increase the viscosity and elasticity of the gel, reducing the damping and increasing the resonance frequency. For the experiment in fig. 14 a) and 14 b), a 40 wt.-% Acrylamide / N, N'- methylenebisacrylamide (19:1) solution is precured by radiation to approximately (or exactly) 42 Gy. As radiation source, a photon beam with 6 MV acceleration voltage and an effective dose rate of 0.1 Gy / s has been used. Similar specifications of the excitation device can also be applied to the embodiments 5 to 7.

[0194] Alternatively, the hydrogel can be produced by providing a hydrogel matrix, for example agarose, and infuse this matrix with the radiation-sensitive solution. This can be done by mixing low percent agarose solution and the previously mentioned acrylamide solution. Similar specifications of the excitation device can also be applied to the embodiments 5 to 7. Molecular species which are responsive to radiation via radical polymerization, such as acrylamide and its derivatives, may be sensitive to dissolved oxygen in solution. Oxygen can inhibit the formation of long polymer chains due to e.g. chain termination mechanisms. Since oxygen is typically present in solutions prepared in normoxic conditions, special measures may be taken to remove the oxygen content in solution (< 0.02 mg / L), e.g. via argon bubbling and device preparation in nitrogen atmosphere, or by using oxygen inhibitors such as tetrakis(hydroxymethyl)phosphonium chloride. Furthermore, natural and artificial light sources may be able to trigger the radical polymerization when the oxygen content is very low. Hence, light exposure of the solution during preparation could be reduced to a minimum, and could be avoided once the solution is within the device, for example, by a light impermeable layer, e.g. aluminum foil.

[0195] The embodiment of fig. 13 has several advantages over mentioned state-of-the-art, inter alia: oscillation may not be affected by changes of the nearby environment; maximum amplitude of the oscillating magnet can always be reached, given that the excitation is sufficient; there may be a very high sensitivity to mechanical and / or dimensional changes of the sensitive component; and larger distances for radiation sensing may be reached.

[0196] Embodiment 5:

[0197] With reference to FIG. 15, in an embodiment, an excitable device 1500 is used for detecting at least one physical and / or chemical parameter. The excitable device 1500 comprising: at least one oscillating magnet 1530 configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; a connecting body 1520 having one part coupled to the at least one oscillating magnet 1530; a housing component 1510; and a sensing material 1570 configured to change at least one mechanical property in response to the at least one physical and / or chemical parameter; wherein the excitable device is configured such that a change of the at least one mechanical property of the sensing material 1570 changes how the at least one oscillating magnet 1530 oscillates; and wherein the connecting body 1520 and the at least one oscillating magnet 1530 are isolated, preferably chemically and / or mechanically, from a surrounding medium by a combination of the housing component 1510 and the sensing material 1570. The at least one oscillating magnet 1530, the connecting body 1520 and the sensing material 1570 are surrounded by a combination of the housing component 1510 and a permeable structure 1560, wherein the permeable structure 1560 is permeable to the at least one physical and / or chemical parameter. The sensing material 1570 is located in a volume defined by the permeable structure 1560.

[0198] The housing component 1510 isolates the oscillating components (oscillating magnet 1530 and connecting body 1520) from direct contact with the environment. A change in oscillation parameters is done over a separate sensing material 1570 which is in contact with the connecting body 1520 or oscillating magnet 1530. The connecting body 1520 does not have to be in direct contact with the housing component 1510. Neither the housing component 1510, nor the connecting body 1520 may be sensitive to the desired physical and / or chemical parameter. Furthermore, the sensing material 1570 is exposed to the environment, through the permeable structure 1560, enabling measurement of, for example, chemical parameters, e.g. pH, biochemicals, antibodies, whereby the oscillating components are still not in direct contact to the environment.

[0199] The sensing material 1570 being located in a volume defined by the permeable structure 1560 may mean that the permeable structure 1560 is in direct contact with the sensing material 1570 on some or all sides. Sides of the sensing material 1570 not in contact with the permeable structure 1560 may be left only limited by the solidity of the sensing material 1570. For example, the side of the sensing material 1570 towards the oscillating magnet 1530 may be without further bordering material.

[0200] The embodiment of fig. 15 has several advantages, inter alia: oscillation is affected indirectly by changes of the nearby environment; maximum amplitude of the oscillating magnet can always be reached, given that the excitation is sufficient; very high sensitivity to mechanical or dimensional changes of the sensitive component.

[0201] In one embodiment, the part or a fraction of the part of the housing component which is contact with the sensing material is perforated to enable an interface between the sensing material and the nearby environment. The perforated part may be the permeable structure. Then, for example chemical changes such as changes in pH, biochemicals, antibodies..., can be detected by the sensing material, which thereby changes its properties, e.g. mechanical stiffness or volume, to influence the oscillation properties. Importantly, the oscillator is not in direct contact to the environment.

[0202] Embodiment 6: With reference to FIG. 16, in an embodiment, an excitable device 1600 is used for detecting at least one physical and / or chemical parameter. The excitable device 1600 comprising: at least one oscillating magnet 1630 configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; a connecting body 1620 having one part coupled to the at least one oscillating magnet 1630; a housing component 1610; and a sensing material 1670 configured to change at least one mechanical property in response to the at least one physical and / or chemical parameter; wherein the excitable device 1600 is configured such that a change of the at least one mechanical property of the sensing material 1670 changes how the at least one oscillating magnet 1630 oscillates; and wherein the connecting body 1620 and the at least one oscillating magnet 1630 are isolated, preferably chemically and / or mechanically, from a surrounding medium by the housing component 1610. The connecting body 1620 is at least partially surrounded by, preferably embedded in, the sensing material 1670. This embodiment 6 is close to embodiment 4, but the connecting body 1620 is not connected to the housing component 1610.

[0203] In one embodiment, the connecting body is an elastic cantilever which is not directly mechanically connected to the housing component. Fabrication of the device using a cantilever not fixed to the housing may be easier because the uncured liquid solution does not have to be poured into the cavity without touching the oscillating magnet and avoiding parts of the housing component and cantilever. Furthermore, this may avoid leading to formation of a meniscus at the interface between air, liquid, and cantilever, potentially strongly impeding the oscillation and leading to undesired or unpredictable changes. To achieve these advantages, the cantilever can be inserted into the hydrogel after gelation. The hydrogel may need to exhibit sufficient mechanical strength to hold the cantilever with magnet in place. A specially designed contraption can improve reproducibility of cantilever insertion. The connecting body 1620 and oscillating magnet 1630 may be attached to a specially designed part (not shown), which can be inserted into the housing 1610 after inserting the liquid sensing material 1670 to avoid the need of prior gelation and to improve reproducibility of fabrication further. This specially designed part behaves as being part of the housing 1610 after assembly of the device and thereby may add to its total mass, which is beneficial to reduce the mechanical coupling to the surrounding environment. The specially designed part may preferably consist of materials which do not affect the functionality of the oscillating magnet (e.g. by being non-conductive and non-magnetic), the connecting body (e.g. by being mechanically rigid), or the sensing material (e.g. by being chemically inert).

[0204] Embodiment 7:

[0205] With reference to FIG. 17, in an embodiment, an excitable device 1700 for detecting at least one physical and / or chemical parameter, the excitable device 1700 comprising: at least one oscillating magnet 1730 configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; a connecting body 1720 having one part coupled to the at least one oscillating magnet 1730; a housing component 1710; and a sensing material 1770 configured to change at least one mechanical property in response to the at least one physical and / or chemical parameter; wherein the excitable device 1700 is configured such that a change of the at least one mechanical property of the sensing material 1770 changes how the at least one oscillating magnet 1730 oscillates; and wherein the connecting body 1720 and the at least one oscillating magnet 1730 are isolated, preferably chemically and / or mechanically, from a surrounding medium. The housing component 1710 is completely surrounded by the sensing material 1770. In alternatives, the housing component 1710 may only be partially surrounded by the sensing material 1770.

[0206] The housing component 1710 may be rigid. The housing component 1710 may be practically rigid, but not 100% rigid. Preferably, the deformability of the housing can be neglected as it is small relative to the deformation of other components including the sensing material 1770. Preferably, the housing component 1710 has a small mass, for example a smaller mass than the oscillating magnet 1730.

[0207] The sensing material 1770 may be injected, e.g. with a needle, after insertion of the housing 1710, connecting body 1720, and magnet 1730 to the surrounding environment. The sensing material 1770 may be injected repeatedly or on-demand and be responsive to different physical and / or chemical parameters. After a use of the excitable device 1700, the "old" sensing material 1770 may be removed or degraded and a "new" sensing material 1770 may be injected. Hence, the excitable device may be reusable.

[0208] Further embodiments, which may be partially or fully combined with embodiments mentioned above, especially embodiment 4 to 7:

[0209] In one embodiment, the connecting body is an elastic cantilever which is mechanically fixed to the housing component. In order to reduce mechanical coupling of the oscillator to the environment, the mass of the housing component may be maximized. If the mechanical properties of the environment are constant or nearly constant, the mechanical coupling may only produce a minor frequency and / or damping offset.

[0210] In one embodiment, the connecting body is partially or fully covered by the sensing material.

[0211] In one embodiment, the sensing material 1770 is consumed or (bio-)degraded over time or in response to the physical and / or chemical parameter, such that after full degradation, a further change of the physical and / or chemical parameter does not affect the oscillation of the magnet 1730. This may especially be implemented in combination with one of embodiments 5 and 7.

[0212] In one embodiment, the position and / or orientation of the excitable device are determined, preferably based on a magnetic field generated by the at least one oscillating magnet of the excitable device, while sensing at least one physical and / or chemical parameter. Determining the position and / or orientation may be performed via e.g. ultrasound, computed tomography, X-rays, or other imaging / tracking technology. It may preferably be performed by using the same magnetic field which is used to detect the at least one physical and / or chemical parameter, since this magnetic field has a special shape in the time-domain when measured with a magnetometer or induction coil. Multiple magnetometers / induction coils and special algorithms, e.g. shown in [3,14], extract the features of the magnetic field during oscillation to enable the calculation of the position and orientation with up to six degrees-of-freedom (three positions and three angular orientations) for a single excitable device. "Determining the position and / or orientation" may be referred to as "localization" or "tracking".

[0213] In one embodiment, position and / or orientation of multiple excitable devices (sensing probes) are determined, preferably based on a magnetic field generated by the at least one oscillating magnet of the excitable device, while respectively sensing at least one physical and / or chemical parameter. To ensure a reliable determination of the position and / or orientation of each respective excitable device, the devices may be not positioned in very close proximity to each other and / or may exhibit different resonance frequencies, if spatial selectivity is important, to avoid simultaneous excitation, signal overlapping, or other interferences.

[0214] In one embodiment, the excitable device comprises an oscillating magnet which rotates around its own axis (torsional oscillator), without the use of an additional magnet to provide a restoring torque.

[0215] In one embodiment, the sensing material may be less depending on dose, but be more sensitive to variation in linear energy transfer of proton / light ion beams.

[0216] The excitable device, especially of embodiments 4 to 7, may also be suited to assess the beam quality in proton and light ion beams. These beams have a different behavior (comparing to gamma radiation), when penetrating tissue, because the particles have a finite range and will stop at a defined point (depending on their energy). The dose delivered to the tissue is increasing towards this end of range and the so-called Bragg peak arises. At the same time, the radiation quality is changing, which is quantified by linear energy transfer (LET). LET will increase in the Bragg peak and even beyond. The LET could affect the polymerization of the hydrogel such, that the polymerization is generally stronger at higher LET, meaning, the excitable device can be used to measure also LET. For this purpose, hydrogels may be used, which are less dependent on dose, but more sensitive to variation in LET. As LET is important for the biological effect in tissue, the sensor and the system may make an important contribution to measure this critical quantity in a patient. Uses in other fields are also possible, as for example experiments on animals or objects. Besides using a hydrogel as sensing material, other kind of elastic or viscoelastic materials are also suitable. Also, composite structures are possible, e.g. hydrogels or rubbers with infused particles or patterned / combined structures, e.g. bottom half of material 1, top half of material 2.

[0217] The excitable device may have size of around 1 mm diameter and 3 mm length. This makes it suitable for needle-based insertion. For improved read-out distance, options exist for optimization, e.g. frequency tuning to avoid noise frequencies, amplitude maximization by using torsional designs, longer signal acquisition, maximization of the magnetic volume.

[0218] The frequency change is not limited to increasing upon change of the physical and / or chemical parameter. It can also decrease, for example upon intentional degradation of the sensing material.

[0219] The damping change is not limited to decreasing upon change of the physical and / or chemical parameter. It can also increase, for example upon intentional decrease of viscosity and / or decrease of elasticity of the sensing material.

[0220] The change in frequency and damping could be independent, i.e. one parameter leads to change of elasticity of the sensing material, which results in a frequency change, while another parameter leads to change of viscosity of the sensing material, which results in a damping change.

[0221] The housing component, connecting body, and oscillating magnet may not be, or as little as possible, sensitive to the physical and / or chemical parameter. This improves the sensing material accuracy.

[0222] Sensing material with reversible functionality are included in this disclosure. In case of irreversible dysfunctionalization of the sensing material during the sensing process, all other parts (magnet, connecting body, and housing) can be reused / recycled by replacement of the sensing material. The excitable device may be fully or partially composed of biodegradable materials to circumvent the required extraction from the surround environment after use.

[0223] While various embodiments of the present disclosure have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. Likewise, the various diagrams may depict an example architectural or configuration, which are provided to enable persons of ordinary skill in the art to understand exemplary features and functions of the present disclosure. Such persons would understand, however, that the present disclosure is not restricted to the illustrated example architectures or configurations, but can be implemented using a variety of alternative architectures and configurations. Additionally, as would be understood by persons of ordinary skill in the art, one or more features of one embodiment can be combined with one or more features of another embodiment described herein. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments.

[0224] It is also understood that any reference to a component herein using a designation such as "first," "second," and so forth does not generally limit the quantity or order of those components. Rather, these designations can be used herein as a convenient means of distinguishing between two or more components or instances of a component. Thus, a reference to first and second components does not mean that only two components can be employed, or that the first component must precede the second component in some manner.

[0225] Additionally, a person having ordinary skill in the art would understand that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits and symbols, for example, which may be referenced in the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. A skilled person would further appreciate that any of the various illustrative logical blocks, units, processors, means, circuits, methods and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two), firmware, various forms of program or design code incorporating instructions (which can be referred to herein, for convenience, as "software" or a "software unit"), or any combination of these techniques.

[0226] To clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, units, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware or software, or a combination of these techniques, depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in various ways for each particular application, but such implementation decisions do not cause a departure from the scope of the present disclosure. In accordance with various embodiments, a processor, device, component, circuit, structure, machine, unit, etc. can be configured to perform one or more of the functions described herein. The term "configured to" or "configured for" as used herein with respect to a specified operation or function refers to a processor, device, component, circuit, structure, machine, unit, etc. that is physically constructed, programmed and / or arranged to perform the specified operation or function.

[0227] Furthermore, a skilled person would understand that various illustrative methods, logical blocks, units, devices, components and circuits described herein can be implemented within or performed by an integrated circuit (IC) that can include a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, or any combination thereof. The logical blocks, units, and circuits can further include antennas and / or transceivers to communicate with various components within the network or within the device. A general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration to perform the functions described herein. If implemented in software, the functions can be stored as one or more instructions or code on a computer- readable medium. Thus, the steps of a method or algorithm disclosed herein can be implemented as software stored on a computer-readable medium.

[0228] Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program or code from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0229] Additionally, memory or other storage, as well as communication components, may be employed in embodiments of the present disclosure. It will be appreciated that, for clarity purposes, the above description has described embodiments of the present disclosure with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic components or domains may be used without detracting from the present disclosure. For example, functionality illustrated to be performed by separate processing logic components, or controllers, may be performed by the same processing logic component, or controller. Hence, references to specific functional units are only references to a suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

[0230] Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other implementations without departing from the scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as recited in the claims below.

[0231] List of references:

[0232] [1] A. Kiourti and R. M. Shubair, "Implantable and ingestible sensors for wireless physiological monitoring: A review," 2017 IEEE International Symposium on Antennas and Propagation & USNC / URSI National Radio Science Meeting, San Diego, CA, USA, 2017, pp. 1677-1678.

[0233] [2] Petar Kassal, Matthew D. Steinberg, Ivana Murkovic Steinberg, "Wireless chemical sensors and biosensors: A review", Sensors and Actuators B: Chemical, Volume 266, 2018, Pages 228- 245.

[0234] [3] Bernhard Gleich et al., "Miniature magneto-mechanical resonators for wireless tracking and sensing", Science 380, 966-971 (2023).

[0235] [4] US 2022 / 0257138 Al

[0236] [5] US 2022 / 0238011 Al

[0237] [6] US 2022 / 0175487 Al

[0238] [7] US 2021 / 0244305 Al

[0239] [8] US 2020 / 0397320 Al

[0240] [9] US 2020 / 0397530 Al

[0241]

[0010] US 2020 / 0397510 Al

[0242]

[0011] US 2020 / 0400509 Al.

[0243]

[0012] F. Fischer, M. Jeong, T. Qiu; Miniature magneto-oscillatory wireless sensor for magnetic field and gradient measurements. Appl. Phys. Lett. 12 August 2024; 125 (7): 074102.

[0244]

[0013] Wan, Ji, et al., "Millimeter-scale magnetic implants paired with a fully integrated wearable device for wireless biophysical and biochemical sensing.", Science Advances, Vol.10, issue 12 (2024).

[0245]

[0014] Fischer, F., Gletter, C., Jeong, M. et al. Magneto-oscillatory localization for small-scale robots, npj Robot 2, 1 (2024).

Claims

New PCT Patent Application Vossius & PartnerDeutsches Krebsforschungszentrum Patentanwalte Rechtsanwalte mbBStiftung des bffentlichen Rechts SiebertstraRe 3DKFZ Ref: P12007PC01 81675 MunchenVossius Ref.: AJ2939 PCT May 23, 2025CLAIMS1. An excitable device for detecting at least one physical and / or chemical parameter, the excitable device comprising: at least one oscillating magnet configured to mechanically oscillate, preferably at a resonance frequency, upon excitation; a connecting body having one part coupled to the at least one oscillating magnet; a housing component; and a sensing material configured to change at least one mechanical property in response to the at least one physical and / or chemical parameter; wherein the excitable device is configured such that a change of the at least one mechanical property of the sensing material changes how the at least one oscillating magnet oscillates; and wherein the connecting body and the at least one oscillating magnet are isolated, preferably chemically and / or mechanically, from a surrounding medium by the housing component or by a combination of the housing component and the sensing material.

2. The excitable device of claim 1, wherein the sensing material is different from the housing component, the connecting body, and / or the at least one oscillating magnet.

3. The excitable device of claim 1 or 2, wherein the excitable device is wireless.

4. The excitable device of any one of the preceding claims, wherein the housing component is at least partially, preferably completely, surrounded by the sensing material.

5. The excitable device of any one of the preceding claims, wherein the at least one oscillating magnet, the connecting body and the sensing material are surrounded by acombination of the housing component and a permeable structure, wherein the permeable structure is permeable to the at least one physical and / or chemical parameter.

6. The excitable device of claim 5, wherein the sensing material is located in a volume defined by the permeable structure.

7. The excitable device of any one of claims 1 to 3, wherein the at least one oscillating magnet, the connecting body and the sensing material are fully isolated from the surrounding medium by the housing component.

8. The excitable device of claim 7, wherein the full isolation is with respect to surrounding solids and liquids, in particular viscoelastic materials and water.

9. The excitable device of claim 7 to 8, wherein the full isolation is with respect to gases, in particular oxygen.

10. The excitable device of any one of the preceding claims, wherein the connecting body is elongated having a long side longer than any other sides of the connecting body, wherein the at least one oscillating magnet coupled to the one part of the connecting body is coupled to an end of the long side.

11. The excitable device of claim 10, wherein another end of the long side is coupled to the housing component.

12. The excitable device of any one of the preceding claims, wherein the connecting body is non-rigid, preferably an elastic component, more preferably a cantilever.

13. The excitable device of any one of the preceding claims, wherein at least one part of the at least one connecting body is coupled to the housing component.

14. The excitable device of any one of the preceding claims, wherein the sensing material comprises at least one of: a hydrogel, viscoelastic materials, elastomers, a natural rubber, a silicone rubber, an elastomer foam, a liquid crystal elastomer, a polymerizable monomer, a gel, an oleogel, an organogel, an aerogel, composite gels, a composite structure of hydrogels or rubbers with infused particles, or patterned or combined structures, and a liquid.

15. The excitable device of any one of the preceding claims, wherein the connecting body is at least partially surrounded by, preferably embedded in, the sensing material.

16. The excitable device of any one of the preceding claims, wherein the housing component and / or the connecting body are insensitive to the at least one physical and / or chemical parameter.

17. The excitable device of any one of the preceding claims, wherein the at least one physical and / or chemical parameter is at least one of: radiation, electric fields, magnetic fields, ultrasound fields, pressure, light, temperature, pH, biomarkers, and biochemicals, glucose.

18. The excitable device of any one of the preceding claims, wherein the at least one mechanical property is viscosity and / or elasticity, wherein the at least one physical and / or chemical parameter is radiation, and wherein the viscosity and / or the elasticity changes in response to the radiation.

19. The excitable device of any one of the preceding claims, wherein the change of the at least one mechanical property of the sensing material changes the resonance frequency and / or damping behavior of the at least one oscillating magnet configured to mechanically oscillate.

20. A system comprising: at least one excitable device of any one of claims 1 to 19;an exciting module configured to excite the at least one excitable device causing an oscillation of the at least one oscillating magnet, preferably by generating at least one external force and / or torque; at least one sensing module configured to sense a magnetic field generated by the at least one oscillating magnet of the at least one excitable device, wherein the sensed magnetic field is associated with the change of the at least one mechanical property of at least one sensing material; and a processing module configured to determine at least one physical and / or chemical parameter based on the sensed magnetic field.

21. A method for detecting at least one physical and / or chemical parameter using at least one excitable device of any one of claims 1 to 19, the method comprising: providing at least one oscillating magnet configured to mechanically oscillate, preferably at the resonance frequency, upon excitation; providing a housing component; providing a connecting body having one part coupled to the least one oscillating magnet; providing a sensing material configured to change at least one mechanical property in response to the at least one physical and / or chemical parameter, wherein the change of the at least one mechanical property of the sensing material changes how the at least one oscillating magnet is configured to mechanically oscillate; exciting the at least one excitable device causing an oscillation of the at least one oscillating magnet, preferably by generating at least one external force and / or torque; determining the resonance frequency and / or damping behavior of the at least one oscillating magnet configured to mechanically oscillate, preferably by sensing a magnetic field generated by the at least one oscillating magnet of the at least one excitable device; and detecting the at least one physical and / or chemical parameter based on the determination of the resonance frequency and / or damping behavior of the at least one oscillating magnet; wherein the connecting body and the at least one oscillating magnet are isolated, preferably chemically and / or mechanically, from a surrounding medium by the housing component or by a combination of the housing component and the sensing material.

22. The method of claim 21, wherein the at least one excitable device is a plurality of excitable devices, the method further comprising: detecting a respective at least one physical and / or chemical parameter using a corresponding respective excitable device from the plurality of excitable devices.

23. The method of claim 21 or 22, the method further comprising: determining a position and / or orientation of the at least one excitable device, preferably based on a magnetic field generated by the at least one oscillating magnet of the excitable device.

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