Temperature sensor and method for producing a temperature sensor

Abstract

The present invention relates to a temperature sensor (100, 110, 120, 130, 140, 150, 160, 170) comprising: a substrate (10, 12, 14); a nanogranular sensor element (20) deposited on the substrate (10, 12, 14); and at least two electrodes (30, 12), which are electrically connected to the sensor element (20) in order to enable measurement of temperature-dependent changes in the conductivity of the sensor element (20).

Description

[0001] Temperature sensor and method for manufacturing a temperature sensor

[0002] Technical field

[0003] The present disclosure relates to temperature sensors capable of performing precise temperature measurements over a defined temperature range and adaptable to various substrates, as well as to a method for manufacturing such temperature sensors.

[0004] State of the art

[0005] Temperature sensors are devices that measure temperature or temperature gradients using various principles. Today, a wide variety of temperature sensors with different properties are available for diverse applications. These sensors can be broadly divided into two types: contact temperature sensors and non-contact temperature sensors. Contact temperature sensors measure their own temperature. The temperature of the surrounding medium can be deduced by ensuring that the sensor is in thermal equilibrium with the surrounding medium. Non-contact temperature sensors measure the temperature of an object by detecting its thermal radiation.

[0006] A common type of contact temperature sensor is a resistance temperature device (RTD), which measures temperature by relating the resistance of the RTD element to the temperature. The element is typically a pure material, often platinum, nickel, or copper. The material has a precise resistance / temperature relationship that is used to provide a temperature reading.

[0007] Thermistors are of particular importance here. They are made of metallic oxides pressed into a small bead, disc, plate, or other shape. They are sintered at high temperatures to stabilize their material properties. Thermistors, derived from the term thermal resistance, are a type of temperature sensor that are simple, inexpensive, and have a large output signal.

[0008] Semiconductor temperature sensors are electronic devices that measure temperature with an electrical output proportional to the temperature. Semiconductor temperature sensors are manufactured using the same technology as transistors, integrated circuits, and microprocessors.

[0009] Despite advances in temperature measurement technology, several technical challenges persist. For example, conventional temperature sensors often lack the ability to be seamlessly integrated into various substrates, limiting their adaptability to different applications. In particular, response times and thermal coupling restrict the use of conventional sensors. Furthermore, the size of traditional sensors can be a limiting factor, especially in applications where space is limited or high spatial resolution is required. However, the size of conventional temperature sensors also results in a large thermal mass that must be heated upon contact with the test object. This can particularly affect the actual temperature of small test objects.Furthermore, the manufacturing methods used for traditional sensors often lack the precision and control to create sensors with specific, tailored properties. For example, it is often challenging to match the temperature response of a sensor to the expected temperature range of the substrate being measured using conventional manufacturing methods. Additionally, traditional sensors often lack the ability to measure temperature over a defined temperature range and / or spatial area, limiting their usefulness in applications requiring detailed thermal mapping and monitoring.

[0010] These unresolved problems and technical challenges underscore the urgent need for improved temperature sensors.

[0011] Description of the invention

[0012] Starting from the known state of the art, it is an object of the present invention to provide an improved device and a corresponding method.

[0013] Accordingly, a temperature sensor is proposed comprising a substrate, a nanogranular sensor element deposited on the substrate, and at least two electrodes electrically connected to the sensor element to enable the measurement of temperature-dependent conductivity changes of the sensor element.

[0014] The electrodes can, for example, be applied to the substrate, and the nanogranular sensor element can then be deposited onto the electrodes and the substrate. The sensor element is in thermal equilibrium with the substrate, so it typically assumes the same temperature as the substrate, allowing the substrate temperature to be measured. However, the temperature of the sensor element determines its electrical resistance. This resistance can be measured using the electrodes.

[0015] The electrical resistance is proportional to the inverse of the electrical conductivity. The electrical conductivity is fundamentally determined by the mobility of electrons within the sensor element. This electron mobility can be adjusted through the manufacturing process itself, as well as through possible post-processing steps, as shown below.

[0016] In principle, it is particularly advantageous if the conductivity is set so that the change in conductivity is at its maximum within the expected temperature range to be measured. By ensuring a particularly large change in conductivity, the temperature can be determined with high accuracy, since even small temperature changes generate large measurement signals. For example, the temperature range to be measured by the sensor element might be between 250 K and 350 K. In this case, it is particularly advantageous if the temperature of maximum conductivity change is around 300 K.

[0017] In particular, the measuring current can also introduce heat into the sensor element. Depending on the application, the resistance of the sensor element can be adjusted, which determines the current, or the voltage of the readout unit can be changed so that the desired temperature changes are not influenced by the heating power of the measuring current. Generally, at the same voltage, a higher resistance leads to lower currents, thus reducing the heating power. The resistance or conductivity measurement is limited by the measurement technology, which is designed to measure the current at a given voltage. The nanogranular sensor element can be deposited locally onto the substrate. Local deposition means that the substrate is not coated globally, but rather the sensor element is deposited only on a specific area of ​​the substrate.

[0018] Deposition can mean that the sensor element is grown on the substrate in a controlled manner through chemical and / or physical processes.

[0019] The term "nanogranular sensor element" is used here to mean that the sensor element consists of, or at least comprises, a nanogranular material. Nanogranular materials offer the advantage that the measurable strain range of the sensor element can be precisely controlled by the shape, form, material, spacing, and number of grains within the sensor element. In particular, the grains can be embedded in a dielectric matrix. The various conductivity mechanisms arise, for example, from the different regimes of the conductivity phase diagram. For instance, thermally activated transport processes dominate in the Arrhenius regime, while different tunneling processes dominate in the inelastic and elastic co-tunneling regimes.In the granular Fermi fluid regime, metallic transport dominates, whereas in the universal behavior regime, conductivity is independent of specific system details.

[0020] In other words, a nanogranular sensor element comprises an ensemble of electrically conductive grains in the nanometer range, whose electrical transport properties are determined by their conductivity, size, spacing, and matrix material. Sensitivity to temperature or radiation arises in particular from effects such as variable range hopping and thermally activated transport.

[0021] In other words, a material described in the literature as nanogranular comprises an ensemble of charge carrier centers that exist in different geometric configurations within at least one matrix material or a mixture of different matrix materials. These charge carrier centers can be distributed homogeneously or inhomogeneously within the matrix material. The electrical transport properties can be determined by material properties (charge carrier density, band structure, and, if applicable, electrical defects due to crystal flaws within the charge carrier centers), the geometric configuration of the charge carrier centers, and their spacing within the matrix.The physical properties of the matrix material (lattice configuration, crystal structure, material) and the individual transition between the matrix material and the individual charge carrier center (transition of the charge carrier center's ligand shell to the matrix, defects) also define the conductivity properties in the nanogranular material. Impurities in the charge carrier centers and in the matrix material also represent defects (essentially, all grain boundaries in the metal, in the matrix, and between the materials, as well as potentially between the materials themselves, are impurities) that are important for charge carrier transport. Furthermore, the interfaces of the nanogranular material with the continuum play a role in defining the conductivity.

[0022] The width of the sensor element can be between 1 nm and 20 pm, preferably between 5 nm and 400 nm, for example 300 nm, and particularly preferably between 8 nm and 12 nm. The height of the sensor element can be between 1 nm and 3 pm, preferably between 5 nm and 400 nm, for example 300 nm or 8 nm.

[0023] The length of the sensor element can be between 1 nm and 20 pm, preferably between 5 nm and 400 nm, for example 300 nm, and particularly preferably between 8 nm and 12 nm.

[0024] The small dimensions of the sensor element enable temperature measurement in any location, especially without major mechanical limitations.

[0025] For example, a sensor element can be mounted directly onto a connector, such as a charging plug, and in particular onto the pin of a charging plug. Due to the small dimensions of the sensor element, the pin can still be inserted securely into the socket, as its dimensions are significantly smaller than the typical tolerances of charging plugs.

[0026] Due to their compact dimensions, such sensors can also be integrated directly into components (into the CPU / processors) and incorporated during the manufacturing process, thus providing, for example, spatially distributed temperature data. This temperature data can refer to general temperature information about the heat source within the CPU, and not to the resulting DI E temperature, since the sensor element is coupled to or within the CPU with very low thermal resistance.

[0027] The mass of the sensor element can range between 1x10 -24 kg and 1x10 -18 kg, preferably between 5x10 -21 kg and 1x10 -18 kg, for example 6x10 -21 kg.

[0028] Due to its low mass, the temperature of the sensor element instantly adapts to the temperature of the environment or the substrate, enabling temperature measurements with high temporal resolution. In particular, this allows temperature changes to be measured quickly.

[0029] For example, the thermal response time T or thermalization time of a sensor element is determined by its characteristic length and the thermal diffusivity a as T = L 2 a. The thermal diffusivity is given by the thermal conductivity k, the heat capacity cp, and the density p of the sensor element as a = k / pc P For a sensor element, for example, c P= 400 J / (kg K), p = 6000 kg / m 3 and k = 40 W / (m K), so that at a characteristic length of L = 10 nm a thermal response within 6 x 10 -12 s is to be achieved. Sensor elements with thermal response times of less than 600 x 10 prove to be particularly advantageous. -9 s is, preferably smaller than 6 x 10 -9 s is, especially preferably smaller than 6 x 10 -12 s be.

[0030] Such short thermal response times make it possible, in particular, to monitor even fast-moving thermal phenomena in real time.

[0031] The sensor element can be in direct contact with the substrate.

[0032] This allows, in particular, for the sensor element to be bonded very firmly to the substrate, thus providing protection against mechanical stresses that could cause the sensor element to detach. Furthermore, the sensor element directly measures the temperature of the substrate, further reducing the thermalization time and improving the temporal resolution of the substrate temperature measurement. In particular, unlike an RTD, there is no or significantly less thermal contact resistance at the interface that could distort the measured resistance, such as that caused by adhesives or thermal pastes applied between the RTD and the heat source.

[0033] In other words, the sensor element makes direct thermal contact with the substrate. This makes it possible, in particular, for the sensor element to provide unadulterated information about the respective heat source.

[0034] The sensor element can be encapsulated with a covering layer.

[0035] The covering layer can cover not only the sensor element itself, but also the electrodes that contact the sensor element. Such electrode covering can also be applied only to specific sections.

[0036] The covering layer protects the sensor element from mechanical or chemical influences.

[0037] However, the covering layer can also act as a thermal barrier.

[0038] Accordingly, the sensor element can be protected from external thermal influences, so that only the temperature of the underlying substrate is measured.

[0039] In the aforementioned example of the temperature sensor on the charging plug pin, it is thus possible to measure only the temperature of the pin and to reduce or eliminate the influence of the charging socket temperature on the measurement result. For the purposes mentioned above, the coating layer can have a thickness between 1 nm and 3 pm, preferably between 25 nm and 400 nm. The thickness of the coating layer is preferably set such that both the nanogranular sensor elements and the electrodes are completely covered by the coating layer.

[0040] The covering layer can also consist of several layers.

[0041] This ensures mechanical and / or thermal protection while keeping the dimensions of the temperature sensor small.

[0042] The substrate can be electrically insulating, wherein the substrate preferably consists of a polymer or a ceramic or comprises a polymer and a ceramic.

[0043] The electrical insulation allows the electrodes to be applied directly to the substrate, thus preventing a short circuit between the electrodes.

[0044] The substrate can be electrically non-insulating, and in particular conductive. The substrate can preferably consist of or comprise a metal or a semiconductor.

[0045] In this case, the sensor element can be in direct contact with the substrate, with an insulating layer arranged between a first electrode and the substrate, and preferably the electrically non-insulating substrate forming the second electrode.

[0046] This eliminates the need for structuring a second electrode, as the conductive substrate forms the second electrode and can be electrically contacted.

[0047] However, it is also possible for the insulating layer to be located beneath the two electrodes. This can simplify the manufacturing process.

[0048] The insulating layer can be, for example, an oxide layer of the substrate such as SiOx, SixNy or TiN, CrN or suitable polymers.

[0049] The substrate can be mechanically flexible.

[0050] Due to its small size, the sensor element can be mounted or embedded in mechanically flexible substrates. For example, a sensor element can be applied to a flexible printed circuit board. This makes temperature measurement possible even within electrical systems such as computers, smartphones, or other telecommunications devices. For instance, such sensors can be integrated into the technical films of batteries, which serve for electrical and thermal insulation. The electrodes can be positioned on both sides of the sensor element.

[0051] For example, the electrodes can be arranged section by section in parallel on the substrate. The sensor element can then be applied to the electrodes in such a way that each electrode contacts the sensor element and the sensor element is in thermal contact with the substrate between the electrodes.

[0052] However, it is also possible that the electrodes are applied to the sensor element in reverse order.

[0053] It is also possible to insert the sensor element flush between the electrodes, so that the top of the sensor element is flush with the top of the electrodes.

[0054] The electrodes can be positioned above or below the sensor element.

[0055] In this case, in addition to the area and the intrinsic electrical properties, such as material and grain size, the thickness of the sensor element determines the electrical resistance.

[0056] For example, an electrically conductive substrate can be used onto which the sensor element is applied. For example, a second electrode can be applied to the sensor element over a flat surface.

[0057] By having the electrodes have a flat shape and not contacting the edges or sides of the sensor element, the manufacturing of the temperature sensors can be simplified.

[0058] In particular, thermoelectric effects, such as the Seebeck effect, can also be measured in such a setup. In this effect, an electrical voltage develops between the electrodes due to a temperature gradient. Because the underside of the sensor element rests flat on the substrate while the top side does not, measurable temperature gradients can arise.

[0059] The temperature sensor can also have four electrodes, with the four electrodes overlapping the sensor element section by section.

[0060] For a rectangular sensor element, the electrodes can be arranged parallel to the short side along the long side. The two outer electrodes, the first and fourth, can supply a current. The two inner electrodes, the second and third, can measure the voltage drop across the sensor element. Various geometric arrangements of the electrodes and the sensor element are possible. For example, the length of the sensor element can be greater than the greatest distance between the electrode contact surfaces. This greatest distance is the distance between the outer edges of the first and fourth electrodes facing away from each other. Alternatively, the length of the sensor element can correspond to the greatest distance between the electrode contact surfaces, so that the sensor element is flush with the first and fourth electrodes.The length of the sensor element can be smaller than the greatest distance between the contact surfaces of the electrodes.

[0061] The first and second of the named variants are particularly preferred, as they allow for especially precise measurements, for example because the streamlines are then distributed particularly homogeneously.

[0062] The temperature sensor can also be used, in particular, in a bridge circuit. A bridge circuit enables a particularly accurate measurement of an unknown electrical resistance by balancing two branches of the bridge circuit, at least one of which contains the unknown electrical resistance.

[0063] In the present case, the sensor element can provide the unknown electrical resistance.

[0064] Typical bridge circuits are known as Wheatstone bridge circuits, FL bridges, or full bridges.

[0065] A bridge circuit consisting of resistors can be interpreted as two voltage dividers connected in parallel, with the bridge arm between their output terminals. The advantage of a bridge circuit over a single voltage divider is that the voltage and current in the bridge arm can be varied not only in magnitude but also in polarity, depending on the resistor settings. Bridge circuits are categorized as 1 / 4 (one variable resistor), 1 / 2 (two variable resistors), and 4 / 4 (four variable resistors).

[0066] For example, each sensor element in the bridge circuit can have a coordinated temperature range. For example, three sensor elements can have a constant conductivity within a defined temperature range, while a fourth sensor element exhibits a maximum change in conductivity within the same temperature range.

[0067] The construction of the bridge circuit is explained in more detail below. Another aspect of the invention is to provide a suitable method for manufacturing the temperature sensor.

[0068] Accordingly, a method for manufacturing a temperature sensor is proposed. The method comprises the following steps: providing a substrate, providing at least two electrodes, depositing a sensor element onto the substrate, and connecting the sensor element to the at least two electrodes to enable the measurement of temperature-dependent conductivity changes of the sensor element.

[0069] This method can be used to manufacture the temperature sensors according to the invention.

[0070] In particular, this method enables the production of sensor elements with a reproducible temperature profile. For example, identical or simultaneous manufacturing ensures that all sensor elements in a batch exhibit the same temperature profile. This means that for each batch, only the temperature profile of a single sensor element needs to be calibrated, or its temperature-resistance curve needs to be known. All other sensor elements can then use this calibration curve. Specifically, this manufacturing process allows for the reproducible production of sensor elements, ensuring that, regardless of the batch, the sensor elements always utilize the same conductivity mechanism, are in the same conductivity regime, or even occupy the same point in the conductivity phase diagram.In this context, a reproducible temperature response can mean that two sensor elements within a temperature window of less than 150 mK exhibit identical electrical resistances. In other words, the measurement error of a temperature measurement can be less than 150 mK.

[0071] The step of providing at least two electrodes can be performed before or after the deposition of the sensor element. Accordingly, in the temperature sensor, the sensor element is positioned above, below, or between the electrodes.

[0072] The connecting step involves establishing electrical contact between the sensor element and the electrodes.

[0073] Various methods are available for the production of nanogranular materials. One possibility is the local production of nanogranular materials through the local application of thermal energy to, for example, precursor materials, with the aim of establishing nanogranularity as a material property.

[0074] In localized fabrication, energy is applied locally to a precursor material, causing it to decompose in place. Chayaka et al., "Nanogranular Co-Al-O films prepared by laser ablation," PSSB 241 72004, describes a process using Cox(Al2O3)1-x as the precursor material. This precursor material is bombarded with pulsed laser beams, altering its properties. This can occur through melting or dissociation, a change of state, or reconfiguration into nanogranularity. With appropriate process control, determined by laser energy, wavelength, pulse duration, and focus, as well as by the suitable precursor material and its composition and grain size, the resulting nanogranular material can consist of, for example, two metals or a metal and a metal oxide.Through local energy application, the nanogranular material is produced on-site on a target substrate at a defined location.

[0075] Local sensor elements can also be produced using a lacquer base. By applying metal compounds dissolved in a carrier solution, such as organometallic compounds, the precursor material can be applied locally via a masking process and then thermally converted. For a lacquer containing metal particles, this is achieved, for example, by sintering or exposure to a laser beam.

[0076] Electron beam-induced or ion beam-induced deposition are further processes in which gaseous molecules are dissociated by an electron or ion beam, resulting in the deposition of non-volatile fragments onto a nearby substrate. The electron or ion beam is typically provided by a scanning electron microscope (SEM) or a focused ion beam (FIB), enabling high spatial accuracy and the production of freestanding three-dimensional structures. The focused electron beam of an SEM or scanning transmission electron microscope (STEM), or the ion beam of an FIB, is frequently used.The precursor materials are typically liquid or solid and are gasified prior to deposition, usually by evaporation or sublimation, and introduced at a precisely controlled rate into the high-vacuum chamber of the electron microscope or the ion beam of an FIB unit. The deposition rate depends on a variety of processing parameters, such as the precursor partial pressure, the substrate temperature, the electron beam parameters, the applied current density or ion density, etc. It is typically on the order of 10 nm / s. The electron beam can also be replaced by other beam types, e.g., ion beams.

[0077] A second possibility for producing nanogranular materials is provided by coating processes.

[0078] By applying energy to precursor materials, target substrates can be coated with nanogranular layers. The target substrate can be equipped with a mask, such as a paint mask, allowing the nanogranular coating to be localized to specific areas on the substrate. In ballistic atomization processes, this localized application to the target substrate can be achieved using shadow masks.

[0079] Silicon-based precursor materials, for example, can be used, which are atomized by applying high amounts of energy. This is the case with processes such as Low-Energy Cluster Beam Deposition (LEBD) or Supersonic Cluster Beam Deposition (CBD). The amount of energy applied to the precursor material controls its growth on the target substrate. With suitable process control, the production of nanogranular materials is possible. Precursor materials can be silicon-based materials, metals, or metal compounds.

[0080] Sputtering processes can also be used to produce nanogranular materials, for example, for the production of CuSiO2 nanogranular films through co-sputtering processes on slightly heated glass substrates (50°C). Process parameters such as chamber vacuum influence the formation of nanogranular films.

[0081] Other processes focus on the production of so-called core-shell structures, in which precursor materials are converted into strontium ferromolybdate / strontium molybdate ceramics. These processes utilize temperatures of several hundred degrees Celsius and high pressures.

[0082] The manufactured nanogranular materials can include, for example, metals, insulators, semiconductors, and dielectrics. For instance, a nanogranular material can also comprise at least one polymer, and in particular, at least one conductive polymer coil. Regardless of the manufacturing process, the nanogranular sensor element can be post-processed to modify the crystal structure and / or grain structure and / or the ligand shell of the crystal or grain, preferably shifting the temperature with the maximum conductivity change into a measurable temperature range.

[0083] The electrical behavior of the sensor element can be specifically tailored by modifying its crystal structure or grain structure. By altering the degree of crystallinity, grain size, or grain spacing, the sensor element's conductivity at a given temperature, or its rate of change at a given temperature, can be adjusted.

[0084] For example, post-processing can consist of transferring energy into the nanogranular material so that the electrical transport properties are adjusted.

[0085] This allows the conductivity change of the sensor element to be optimized for a wide temperature measurement range.

[0086] Post-processing can also consist of annealing, particularly local laser annealing. In this process, the sensor element is heated locally, so that the thermal motion can, for example, induce crystallization of the sensor element, thereby adjusting its conductivity.

[0087] In general, the sensor element can be thermally post-treated, for example by heating or by subjecting it to an electron or

[0088] Laser beam. Ultimately, energy is applied to the material, thereby initiating formation processes that influence the material properties. For example, post-irradiation with high-energy electrons at several keV can be performed. However, it is also possible to simply heat the sensor elements, for example at 450°C for one hour.

[0089] The process may also include the step of providing the electrodes, as well as the step of providing an insulating layer.

[0090] Furthermore, the process may include a step of providing a cover layer.

[0091] Furthermore, a medical instrument is proposed that includes a treatment head for treating a patient and that includes at least one temperature sensor arranged on the treatment head, as described above. The temperature sensor allows the medical instrument to be monitored and / or the treatment performed with the medical instrument to be monitored, regulated, and / or controlled.

[0092] The nanogranular sensor element of the temperature sensor can be deposited directly onto the treatment head as a substrate. In other words, the nanogranular sensor element can be in direct contact with the treatment head material and / or be arranged on a layer placed on the treatment head, for example, an insulating layer. This enables immediate and efficient measurement of the treatment head's temperature.

[0093] The treatment head can be set up to carry out a thermal treatment process, preferably to carry out a thermal treatment process.

[0094] For example, the treatment head can be designed for laparoscopic or minimally invasive procedures. However, it can also be designed for open surgery.

[0095] For example, the treatment head can be designed as the treatment head of a coagulator, an electrocautery, a plasma coagulator, a plasma ablation instrument, a laser ablation instrument, or a resection instrument.

[0096] The temperature sensor can be used to measure a temperature that serves to control or regulate the energy supply to the treatment head. In other words, the temperature sensor enables fast and precise control of the treatment energy at the treatment site.

[0097] Alternatively or additionally, temperature measurement can be used to document a treatment or to inform the treating physician.

[0098] Brief description of the characters

[0099] Preferred further embodiments of the invention are explained in more detail by the following description of the figures. These show:

[0100] Figure 1 shows a cross-sectional view of a first embodiment of a

[0101] Temperature sensor, wherein the sensor element is applied to and encapsulated on an insulating substrate and is electrically contacted via electrodes, Figure 2 shows a cross-sectional view of a temperature sensor in a second embodiment, wherein the sensor element is applied to an electrically non-insulating substrate,

[0102] Figures 3A and 3B show cross-sectional views of a temperature sensor in a third and fourth embodiment, wherein the sensor element is applied to an electrically non-insulating substrate.

[0103] Figure 4 is a very schematic representation of a section of a temperature sensor configuration in which a sensor element and a contacting material of an electrode are selected such that a passive temperature sensor (thermocouple) is created in which a Seebeck effect can be measured.

[0104] Figures 5A, B, C show different embodiments of layouts of a temperature sensor in which a sensor element is contacted with two pairs of electrodes for voltage-correct measurement.

[0105] Figure 6 shows a schematic diagram of the measuring circuit provided by the temperature sensor of Figures 5A-5C,

[0106] Figure 7 shows a schematic diagram of a temperature sensor integrated into a Wheatstone bridge configuration,

[0107] Figure 8 shows a schematic diagram of a high-precision temperature sensor incorporating a Wheatstone bridge configuration,

[0108] Figure 9 shows a schematic diagram of a high-precision temperature sensor comprising a Wheatstone bridge configuration in a particularly advantageous arrangement,

[0109] Figure 10 shows a cross-section of a temperature probe tip in a first embodiment,

[0110] Figure 11 shows a cross-section of an arrangement of an additional temperature probe tip,

[0111] Figure 12 shows a view of a flexible printed circuit board,

[0112] Figure 13 shows a schematic cross-sectional view of a flexible printed circuit with an integrated temperature sensor; Figures 14A and 14B each show a view of a pin of an electrical connector with an attached temperature sensor, as well as a close-up of the respective area of ​​the pin on which the temperature sensor is mounted;

[0113] Figure 15 shows a schematic representation of the manufacturing process;

[0114] Figures 16A and 16B show schematic views of a medical device with an attached temperature sensor; and

[0115] Figure 17 shows a schematic view of a medical device with an attached temperature sensor in a further embodiment.

[0116] Detailed description of preferred implementation examples

[0117] Preferred embodiments are described below with reference to the figures. Identical, similar, or equivalent elements in the different figures are designated with identical reference numerals, and repeated descriptions of these elements are sometimes omitted to avoid redundancy.

[0118] The present disclosure provides temperature sensors with nanogranular sensor elements that are not only compact in size and have a very small mass, but can also be applied directly to a substrate. For example, the size of the sensor element can be as small as 10 nm x 10 nm x 10 nm, while the weight is only about 6 x 10 -21 The weight is kg. This allows for a direct, accurate and rapid measurement of the temperature of any substrate.

[0119] For example, the thermal response time T or thermalization time of a sensor element is determined by its characteristic length and the thermal diffusivity a as T = L 2 / a. The thermal diffusivity is given by the thermal conductivity k, the heat capacity c P as well as the density p of the sensor element to a = k / pc P For a sensor element, for example, c P = 400 J / (kg K), p = 6000 kg / m 3 and k = 40 W / (m K), so that at a characteristic length of L = 10 nm a thermal response within 6 x 10 -12 is possible.

[0120] The mass allows us to infer a thermalization time during which even individual temperature fluctuations can be detected. The thermalization time of such small sensor elements, which is on the order of a few picoseconds, enables the detection of temperature fluctuations in the 100 GHz range. This allows, for example, processor systems to be monitored with regard to their energy consumption per processing cycle, so that in the event of a sudden temperature increase, such as that caused by ransomware, major damage can be avoided and appropriate countermeasures can be taken.

[0121] Due to their small possible structure size, the temperature sensors also enable a high spatial resolution.

[0122] These advantages make the temperature sensors proposed here suitable for a wide variety of applications that require precise and robust temperature measurements.

[0123] With reference to Figure 1, a temperature sensor 100 is shown in a schematic cross-sectional view. The temperature sensor 100 comprises a nanogranular sensor element 20, which is positioned on an electrically insulating substrate 10.

[0124] The sensor element 20, for example, has a width, height, and / or length between 1 nm and 3000 nm. In particular, the mass of such a sensor element 20 is between 1 x 10 -24 kg and 1x10 -18 kg. The substrate 10 can, for example, be a mechanically flexible substrate 14. In particular, the sensor element 20 is in direct contact with the electrically insulating substrate, which can be, for example, a polymer or a ceramic.

[0125] The sensor element 20 is electrically contacted by two electrodes 30 positioned on either side of the sensor element 20. These electrodes 30 enable the measurement of temperature-dependent conductivity changes of the sensor element 20. In other words, when the temperature of the sensor element 20 changes, its electrical conductivity, or rather its electrical resistance, also changes. This change in conductivity can be measured via the contact by means of the electrodes 30 and provides a means of determining the temperature of the sensor element 20 as well as—assuming thermal equilibrium between the sensor element 20 and the substrate—of the underlying substrate 10, 14. In other words, the sensor element 20 is the element of the temperature sensor 100 that responds in a defined manner to the temperature change and thus dominates or makes the measurement possible.

[0126] The sensor element 20 and the electrodes 30 can be encapsulated in a cover layer 40. This cover layer 40 serves as a protective sheath and shields the sensor element 20 and the electrodes 30 from external environmental influences. In particular, the cover layer can act as a thermal barrier, thus isolating the sensor element from parasitic thermal influences. For example, the cover layer 40 can have a thickness of 1 nm to 100 nm. This cover layer 40 therefore ensures the stability and longevity of the temperature sensor 100 and thus enables long-term use in various applications and under harsh conditions.

[0127] In some aspects, the temperature sensor 100, and thus the sensor element 20, can be used for measuring reaction heat or for calorimetry. Due to its small size and the properties of the materials used, the sensor element 20 reacts quickly to the generated heat. This enables the sensor element 20 to measure temperature changes rapidly and provides accurate and reliable temperature measurements in calorimetric applications.

[0128] With reference to Figure 2, a temperature sensor 100 is shown in a second embodiment. In this embodiment, the sensor element 20 is positioned on an electrically non-insulating substrate 12. The electrically non-insulating substrate 12 can be a conductive material, such as a metal or a semiconductor. The electrically non-insulating substrate 12 can, for example, be a component of a device, such as the pin of a connector, in which temperature measurements are desired.

[0129] In some cases, an insulating layer 60 is arranged between at least one of the electrodes 30 and the electrically non-insulating substrate 12. The insulating layer 60 serves to electrically isolate the electrode 30 from the electrically non-insulating substrate 12 and to reduce or prevent electrical interference from the electrically non-insulating substrate 12 that could potentially affect the measurement of temperature-dependent conductivity changes of the sensor element 20. In this way, a short circuit between the electrodes 30 via the electrically non-insulating substrate 12 is also avoided.

[0130] Analogous to Figure 1, the sensor element 20 is deposited onto the insulating layer 60 and the electrodes 30; in addition, the sensor element 20 and the electrodes 30 can also be encapsulated with a covering layer 40.

[0131] As shown in Figure 2, the insulating layer 60 can also be arranged beneath the sensor element 20. If the sensor element 20 has a lower specific resistance, i.e., a higher conductivity, than the substrate 10, then the insulating layer 60 beneath the sensor element 20 can be omitted. The conductivity ratio must be greater than the smallest measurable change in the resistance of the sensor element 20. Accordingly, the conductivity ratio can be smaller if the conductivity of the sensor element 20 changes significantly than if it changes only slightly. Referring to Figure 3A, a temperature sensor 100 is shown in a third embodiment. In this embodiment, the sensor element 20 is positioned on an electrically non-insulating substrate 12, analogous to Figure 2.

[0132] The sensor element 20 is electrically contacted by a first electrode 30, which is positioned on one side of the sensor element 20 and is insulated from the electrically non-insulating substrate 12 by an insulating layer 60. The sensor element 20 is in direct electrical contact with the electrically non-insulating substrate 12, which serves as a second electrode 30 for contacting the sensor element 20 to measure a change in conductivity.

[0133] Referring to Figure 3B, a temperature sensor 100 is shown in a fourth embodiment. In this embodiment, the sensor element 20 is positioned on an electrically non-insulating substrate 12, analogous to Figure 2. However, the first electrode is applied to the sensor element.

[0134] Due to the small dimensions of the sensor element, precise electrode positioning is unnecessary, as the electrode can be applied as a film over the sensor element 20. This greatly simplifies the structuring of the electrodes, since positioning accuracy of a few nanometers is not required to bring the sensor element 20 into contact with the electrodes 30.

[0135] In this case, however, the change in resistance is measured perpendicular to the surface of the substrate. This allows for the exploitation of other thermoelectric effects as well. For example, the thermoelectric effect could be the Seebeck effect, the Peltier effect, or the Thomson effect.

[0136] In particular, depending on the material pairing between the sensor element 20 and the electrically non-insulating substrate 12, a passive thermocouple can also be obtained which utilizes thermoelectric effects.

[0137] The Seebeck effect also depends, for example, on the granularity, i.e. the grain size and grain spacing, of the sensor element 20, so that the method shown below can also be used directly to adjust the Seebeck coefficient.

[0138] With reference to Figure 4, a schematic configuration of a passive thermocouple 110 is shown. The Seebeck effect is a phenomenon in which a temperature difference between two different electrical conductors or semiconductors generates a voltage difference at the junction between the two substances. In the context of the passive thermocouple 110 described here, the sensor element 20 and the electrode 30 can be made of different materials, and a temperature difference at the junction between them can generate a voltage difference via the Seebeck effect, which can be measured to determine the temperature.

[0139] In this embodiment, the sensor element 20 is positioned adjacent to the electrode 30, forming a compact and integrated unit. The sensor element 20 and the electrode 30 are in direct contact, enabling efficient thermal energy transfer between them and thus temperature equalization. This arrangement facilitates the generation of a voltage difference due to the Seebeck effect when a temperature difference exists between the sensor element 20 and the electrode 30.

[0140] Alternatively, the contact point generating the Seebeck effect can be provided between the sensor element 20 and the electrically non-insulating substrate 12. With a suitable material pairing between the electrically non-insulating substrate 12 and the sensor element 20, the formation of the passive thermocouple 110 is also possible, for example, in the embodiment shown in Figure 3A.

[0141] With reference to Figures 5A to 5C, various circuit arrangements of a temperature sensor 100 are shown. In these configurations, the sensor element 20 is electrically connected to a first pair of electrodes 32 and a second pair of electrodes 34.

[0142] The first pair of electrodes 32 is connected to a voltmeter 70. The voltmeter 70 measures the voltage drop across the sensor element 20 between the contact areas with the electrodes 32.

[0143] A constant current source 72 is connected to the second pair of electrodes 34. The first pair of electrodes 32 lies between the second pair of electrodes 34.

[0144] The constant current source 72 supplies a stable, constant current that flows between the contact areas of the electrodes 34 and through the sensor element 20. This ensures a uniform voltage distribution within the sensor element 20.

[0145] The proposed contact and circuit configuration allows for a voltage-correct measurement of the voltage using the voltmeter 70. The voltage varies with temperature, thus indicating the temperature-dependent change in the resistance of the sensor element 20. This setup enables precise measurement of the resistance of the sensor element 20 and its temperature-dependent changes.

[0146] In some embodiments, the sensor element 20 is deposited on the electrodes 30 such that it overlaps them at least partially. Figures 5A to 5C show different degrees of overlap between the sensor element 20 and the electrode pair 34. These varying degrees of overlap do not result in different voltage measurements at the inner pair of electrodes 32, thus enabling a stable manufacturing process.

[0147] Figure 6 shows a schematic diagram of the measuring circuit provided by the embodiment of the temperature sensor 100 in Figures 5A to 5C. The sensor element 20 is connected to the first pair of electrodes 32 and the second pair of electrodes 34. The first pair of electrodes 32 lies within the second pair of electrodes 34 on the sensor element 20.

[0148] A voltmeter 70 is connected to the first pair of electrodes 32. The voltmeter 70 is designed to measure the voltage difference across the sensor element 20, which corresponds to the temperature-dependent changes in the resistance of the sensor element 20.

[0149] A constant current source 72 is connected to the second pair of electrodes 34. The constant current source 72 supplies a constant and stable current across the sensor element 20, ensuring a uniform voltage distribution within the sensor element 20.

[0150] This device enables an accurate measurement of the resistance of the sensor element 20 and its temperature-dependent changes.

[0151] This circuit ensures a voltage-correct measurement.

[0152] With reference to Figure 7, a high-precision temperature sensor 120 with a sensing element 20 is shown. The temperature sensor 120 comprises a Wheatstone bridge 700 in which the sensing element 20 is accommodated. The Wheatstone bridge 700 is a known electrical circuit used to measure an unknown electrical resistance by balancing two bridge arms, one of which contains the unknown component. In this case, the sensing element 20 is the unknown resistance, the resistance of which changes in response to temperature variations. The Wheatstone bridge 700 comprises four resistors: the sensing element 20 with the first resistor R1, and three conventional resistors 76 with the second resistor R2, the third resistor R3, and the fourth resistor R4.

[0153] The sensor element 20 exhibits a temperature dependence of its resistance R1. The three other resistances R2, R3, R4 of the Wheatstone bridge 700 are formed by conventional resistors 76, which do not have such a temperature dependence in their resistances. The three conventional resistors can be identical.

[0154] A constant current source 72 is connected to the Wheatstone bridge 700 to provide a stable current. A voltmeter 70 is connected across the bridge to measure the voltage changes corresponding to the temperature variations detected by the sensor element 20. This setup ensures precise temperature measurement by utilizing the Wheatstone bridge 700 for increased sensitivity and accuracy.

[0155] With reference to Figure 8, a high-precision temperature sensor 130 in a configuration with a Wheatstone bridge 700 is shown. The Wheatstone bridge 700 comprises four resistors, designated R1, R2, R3, and R4. The sensor element 20, connected by the electrodes 30, has the temperature-dependent first resistance R1 and forms the first resistance of the Wheatstone bridge 700. The three other resistances R2, R3, and R4 of the Wheatstone bridge 700 are each formed by reference sensor elements 22. The reference sensor elements 22 can be manufactured by a process identical to that of the sensor element and also exhibit a temperature dependence of their respective resistances R2, R3, and R4.

[0156] In the embodiment shown, the three reference sensor elements 22 are manufactured from the same material combination using the same method, so that the temperature dependence of the three reference sensor elements 22 is identical or nearly identical.

[0157] A constant voltage source 74 is connected to the Wheatstone bridge 700. The constant voltage source 74 provides a stable voltage across the Wheatstone bridge 700. A voltmeter 70 is connected across the Wheatstone bridge 700 to measure the voltage difference, enabling precise measurement of temperature-dependent conductivity changes in the sensor elements 20. The voltage difference measured by the voltmeter 70 corresponds to the temperature-dependent changes in the resistance of the sensor elements 20. To obtain a highly accurate measurement of the temperature-dependent resistance change in the high-precision temperature sensor 130, the sensor element 20 is preferably manufactured such that its resistance R1 exhibits a significant temperature dependence in the relevant temperature range. Preferably, however, the resistances R2, R3, R4 of the reference sensor elements 22 do not change in the temperature range of interest.

[0158] All sensor elements 20 and all reference sensor elements 22 are brought to the same temperature to be measured - preferably they are all grown on the same substrate.

[0159] For example, sensor elements 22 do not change their resistance significantly or at all in a temperature range up to 100 K, but sensor element 20 reacts strongly in this range. This allows, for example, highly precise low-temperature measurements, such as in a cryostat. Conventional ohmic resistors would not be suitable for low-temperature measurements.

[0160] This different behavior of the sensor element 20 and the reference sensor elements 22 with respect to the temperature dependence of their respective resistances can be achieved by assembling the sensor element 20 and the reference sensor elements 22 from different materials and / or by post-processing them differently.

[0161] Furthermore, if the temperature is to be measured over a large temperature range, it can be particularly advantageous to cascade temperature sensors with different temperature ranges, so that the temperature range to be measured is covered by a large number of temperature sensors.

[0162] With reference to Figure 9, a high-precision temperature sensor 140 with a Wheatstone bridge 700 is shown. The Wheatstone bridge 700 comprises four resistors, designated R1, R2, R3, and R4. The sensor element 20, connected by the electrodes 30, forms the first resistor R1 of the Wheatstone bridge 700. A second sensor element 20 forms the opposite resistor R4 of the Wheatstone bridge 700. The two other reference sensor elements 22 form the resistors R2 and R3 of the Wheatstone bridge 700.

[0163] The reference sensor elements 22 are made from the same material combination using the same manufacturing process, so that the temperature dependence of the reference sensor elements 22 is identical or nearly identical.

[0164] The two sensor elements 20 are manufactured from the same material combination using the same manufacturing process, so that the temperature dependence of the sensor elements 20 is identical or nearly identical. A constant voltage source 74 is connected to two of the nodes of the Wheatstone bridge 700. A voltmeter 70 is connected to the other two nodes via the Wheatstone bridge 700 to measure the voltage difference, which enables a precise measurement of temperature-dependent conductivity changes of the sensor element 20.

[0165] All sensor elements 20 and all reference sensor elements 22 are brought to the same temperature to be measured - preferably they are all grown on the same substrate.

[0166] To obtain a highly accurate measurement of the temperature-dependent resistance change in the high-precision temperature sensor 140, the sensor elements 20 are preferably manufactured such that their resistances R1, R4 exhibit a significant temperature dependence in the relevant temperature range. Preferably, in the same embodiment, the resistances R2, R3 of the reference sensor elements 22 do not change with respect to their resistances in the temperature range of interest.

[0167] For example, sensor elements 22 do not change their resistance significantly or at all in a temperature range up to 50 K, but sensor elements 20 react strongly. This also allows, for example, highly precise low-temperature measurements to be carried out in a cryostat.

[0168] In particular, this allows two different temperature measurement ranges to be covered and precisely measured with the same temperature sensor, since the reference sensor elements 22 exhibit a high temperature dependence in a first temperature range and the sensor elements 20 exhibit a low or negligible temperature dependence in the first temperature range, whereas in a second temperature range the reference sensor elements 22 exhibit a low or negligible temperature dependence and the sensor elements 20 exhibit a high temperature dependence. In a sense, the reference sensor elements 22 and the sensor elements 22 exchange roles when switching from the first temperature range to the second temperature range.

[0169] Due to the small dimensions of the sensor element, it is also possible to provide a large number of Wheatstone bridges on the substrate, with each Wheatstone bridge being able to determine the temperature particularly accurately in a specific temperature range.

[0170] However, it is also possible that resistors R2 and R3 have a temperature coefficient opposite to that of R1 and R4. This results in a particularly strong measurement signal. This different behavior of the sensor elements 20 and the reference sensor elements 22 with respect to the temperature dependence of their respective resistances can be achieved by depositing the sensor elements 20 and the reference sensor elements 22 using different manufacturing processes and / or by post-processing the sensor elements 20 and the reference sensor elements 22 differently.

[0171] With reference to Figure 10, a temperature sensor in the form of a temperature probe tip 150 is shown. The temperature probe tip 150 comprises a sensor element 20 which is positioned on an insulating substrate 10.

[0172] The sensor element 20 is electrically contacted by two electrodes 30, which are positioned on either side of the sensor element 20. These electrodes 30 enable the measurement of temperature-dependent changes in the conductivity of the sensor element 20. In other words, when the temperature of the sensor element 20 changes, its electrical conductivity also changes. This change in conductivity can be measured by the electrodes 30 and provides a means of determining the temperature of the sensor element 20.

[0173] The sensor element 20 and the electrodes 30 can be encapsulated in a cover layer 40. This cover layer 40 serves as a protective housing and shields the sensor element 20 and the electrodes 30 from external environmental influences, so that the temperature probe tip 150 has a particularly long service life.

[0174] With reference to Figure 11, an alternative arrangement of a temperature probe tip 150 is shown. In this embodiment, the sensor element 20 is positioned at the tip on an insulating substrate 10. The insulating substrate 10 serves as a base layer for the sensor element 20 and provides a stable platform for it. The insulating substrate 10 can be made of an electrically insulating material, such as ceramic or a polymer, to prevent any electrical interference that could potentially affect the measurement of temperature-dependent conductivity changes in the sensor element 20. The sensor element 20 must be subjected to thermal energy flow, ensuring particularly good thermal coupling of the sensor element.

[0175] The sensor element 20 is flanked on both sides by two electrodes 30, which establish electrical contact with the sensor element 20 and enable the measurement of temperature-dependent conductivity changes. The electrodes 30 serve as conductive paths for the electrical signals generated by the sensor element 20 in response to temperature changes. These signals can then be transmitted to other components of the temperature probe tip 150 or to an external device for further processing and analysis. Analogous to Figure 10, this temperature probe tip 150 can also have a covering layer 40.

[0176] With reference to Figure 12, a flexible printed circuit 160 is shown. The flexible printed circuit 160 comprises several parallel conductive tracks designed for electrical connections. For example, the sensor element 20 can be applied to the flexible printed circuit 160 and then encapsulated with the printed circuit board material.

[0177] Figure 13 shows a schematic cross-sectional view of a flexible printed circuit 160, as shown in Figure 12.

[0178] The flexible printed circuit 160 consists of a flexible substrate 14, which serves as the base layer. Outer functional layers 16 are arranged on the flexible substrate 14. The flexible printed circuit 160 is designed to be able to assume various shapes, which increases its adaptability for different applications.

[0179] A temperature sensor 100 can be integrated into the flexible printed circuit 160. The temperature sensor 100 comprises a sensor element 20, which is deposited on the flexible substrate 14. The sensor element 20 is electrically contacted by two electrodes 30, which enable the measurement of temperature-dependent conductivity changes of the sensor element 20.

[0180] The sensor element 20 and the electrodes 30 are encapsulated in a cover layer 40. This cover layer 40 serves as a protective housing and shields the sensor element 20 and the electrodes 30 from external environmental influences. This housing ensures the stability and longevity of the sensor and makes it suitable for long-term use in various applications.

[0181] In other aspects, the flexible printed circuit 160 can be used in a variety of applications requiring flexible and adaptable electronic components. For example, the flexible printed circuit 160 can be used in portable devices, flexible electronics, or other applications where the circuit is expected to adapt to different shapes and surfaces. The high spatial resolution of the sensor element 20, combined with its adaptable temperature response, makes the temperature sensor 100 a versatile and adaptable solution for temperature measurement and monitoring in a flexible printed circuit configuration. The sensor element 20 can be used accordingly in a flexible printed circuit (FPC) 160. The FPC 160 provides a flexible and adaptable platform for integrating the sensor element 20.The flexibility of the FPC 160 allows it to adapt to various shapes and surfaces, making it suitable for applications where the sensor element 20 needs to be mounted on non-flat or flexible surfaces. The high flexibility of the sensor element 20 within the flexible printed circuit, combined with its adjustable temperature response, makes it a versatile and adaptable solution for temperature measurement and monitoring in an FPC configuration.

[0182] In particular, the flexible printed circuit with the sensor element 20 can be attached to flat or curved surfaces whose temperature is to be measured or monitored. This enables temperature monitoring of critical parts in manufacturing plants, and in particular, machine failures can be predicted using predictive maintenance.

[0183] With reference to Figures 14A and 14B, a temperature sensor 100 mounted on a pin of an electrical connector 170 is shown. The pin of the electrical connector 170 could be contained in a plug to connect the battery of an electric car to a charger. The temperature sensor 100 on the pin of the connector 170 serves to measure the temperature of the pin of the electrical connector 170. The temperature could be relevant to determine whether a charging current is too high for the specification of the electrical connector.

[0184] In this embodiment, the electrically non-insulating substrate 12 is configured as the pin of the electrical connector 170. The pin of the electrical connector 170 can be made of a conductive material, such as metal, and serve as the base layer for the sensor element 20. The pin of the electrical connector 170 can also be a component of a device, such as a connector for connecting an electric car battery to a charger, where temperature measurements are desired.

[0185] The sensor element 20 can be deposited onto the electrically non-insulating substrate 12 or an intermediate insulating layer using one of the methods mentioned above. After deposition, the sensor element 20 can be adjusted with respect to its Coulomb barrier by post-irradiation. This adjustment makes it possible to match the temperature response of the sensor element 20 to the expected temperature range of the substrate to be measured. Figure 14a shows the pin of the electrical connector 170 including the temperature sensor 100. The sensor element 20 is arranged on the curvature of the pin. The pin material is an electrically conductive material, i.e., an electrically non-insulating substrate 12. The temperature sensor 100, in particular the sensor element 20, is applied directly to the non-insulating substrate 12.In other words, the temperature sensor 100 is applied directly to the element or material whose temperature is to be measured. The temperature sensor can be positioned at any location on the pin, for example, at a particularly advantageous point.

[0186] In the embodiment shown, two electrodes 30 are provided to contact the sensor element 20, so that an insulating layer (not shown in this figure) is present between the non-insulating substrate 12 (i.e. the metallic material of the pin) and the electrodes 30 and the sensor element 20.

[0187] In an alternative embodiment, not shown in Figure 14a, the sensor element 20 could be contacted by a single electrode 30 that is insulated from the pin material. The other electrode is then provided by the pin material, which in this embodiment is not insulated from the sensor element 20.

[0188] In some cases, an insulating layer 60 is arranged between the electrode 30 and the non-insulating substrate 12. The insulating layer 60 serves to electrically isolate the electrode 30 from the non-insulating substrate 12 and to prevent any electrical interference from the non-insulating substrate 12 that could potentially affect the measurement of temperature-dependent conductivity changes of the sensor element 20.

[0189] Figure 14b shows the pin of an electrical connector 170 including the temperature sensor 100. The temperature sensor 20 is arranged on a flat surface of the pin. The pin material is an electrically conductive material, i.e., an electrically non-insulating substrate 12. The temperature sensor 100, in particular the sensor element 20, is applied to the non-insulating substrate 12 on an insulating layer 60. The temperature sensor 20 can be arranged at any location, e.g., at a particularly advantageous position on the pin.

[0190] The figure provides a detailed view of the temperature sensor 100, highlighting the sensor element 20 and its connection to the first pair of electrodes 32 via the second pair of electrodes 34. This arrangement corresponds to that shown in Figures 5A to 5C. In some of the aforementioned cases, the nanogranular sensor element 20 is adapted with respect to its Coulomb barrier by post-irradiation. By adjusting the Coulomb barrier of the sensor element 20, the temperature response of the sensor element 20 can be tailored to suit the expected temperature range of the substrate to be measured.

[0191] This adaptation can be achieved, for example, by applying a selected post-processing that leads to a specific crystallite size and spacing distribution, which in turn is specific to the Coulomb barrier for a material combination (charge carrier center & dielectric).

[0192] However, it is also possible that the manufacturing parameters used in the production process create sensor elements with a specific granularity, including a specific grain size and spacing. By adjusting the size and spacing, the Coulomb barrier can also be adjusted. The Coulomb barrier can be set so that it coincides with the thermal energy kbT in the temperature range being measured.

[0193] Figure 15 shows a schematic representation of the fabrication process using electron beam induced deposition (EBID) of the nanogranular sensor element. This fabrication process enables the temperature sensor to be seamlessly deposited into or integrated into various substrates, thereby increasing its adaptability in diverse applications.

[0194] For example, the nanogranular sensor elements 20 shown in Figures 1 to 14 can be generated using EBID.

[0195] In a first step S1, a substrate is therefore provided in the coating system.

[0196] In a second step S2, a precursor gas is introduced in the immediate vicinity of the electron beam focus, with the electron beam focus located on the substrate surface.

[0197] In a third step S3, which may also precede the first step in the sequence of events, electrodes can be pre-structured on the substrate surface using standard lithography techniques, so that the sensor element is applied to the electrodes.

[0198] However, it is also possible that the electrodes are applied to the substrate only after the sensor element has been fabricated, so that the third step S3 occurs after the second step S2. In a fourth step S4, the substrate is described by guiding the electron beam across it in a raster pattern.

[0199] However, it is also possible that the sensor elements 20 are manufactured using pulsed laser deposition. Laser evaporation processes are also conceivable, for example, cluster deposition processes of clusters on the order of a few nanometers, or sputtering processes, in particular co-sputtering processes, in which the components of the sensor element are simultaneously deposited onto the substrate.

[0200] In the above methods, the local sensor elements can be created by appropriately masking the substrate before the coating process.

[0201] In a fifth step, the nanogranular sensor elements 20 can be post-processed, in particular post-irradiated, which allows the Coulomb barrier of the nanogranular sensor element 20 to be adjusted.

[0202] The various temperature sensor configurations revealed here are industrially applicable due to their versatile and adaptable design across a wide range of industries. The sensor's compact size, high spatial resolution, and adjustable temperature response make it suitable for precise temperature measurements in diverse applications.

[0203] In the electronics industry, the temperature sensor can be seamlessly integrated into various components such as cables, pins, connectors, probes, and semiconductor components like CPUs and GPUs. This enables direct temperature measurement of these components and provides valuable information for thermal management and performance monitoring. The sensor can also be integrated into flexible printed circuit boards, making it suitable for applications in flexible electronics and wearable devices.

[0204] In the manufacturing industry, the temperature sensor can be used for thermal process control. Its high spatial resolution enables detailed thermal mapping and monitoring, which is particularly useful in processes requiring precise temperature control. The sensor can also be used to measure the temperature distribution on wafers in the semiconductor industry, providing a detailed map of the temperature distribution across the wafer, which can help improve the manufacturing process.

[0205] In the medical industry, the temperature sensor can be used in various medical devices and procedures. For example, it can be integrated into ablation catheters to measure temperature during cancer therapy, providing real-time feedback to ensure the effectiveness and safety of the treatment. The sensor can also be encapsulated and sterilized for use in medical probes or catheters, making it suitable for invasive temperature measurements.

[0206] In some versions, the temperature sensor can be used for other medical applications, such as measuring the temperature of mammals, including humans and animals, to determine if they have a fever or are suffering from hypothermia. When deposited on a biocompatible, flexible substrate, the sensor element can be designed to conform to the contours of a mammal's body, enabling non-invasive and continuous temperature monitoring.

[0207] In some versions, the temperature sensor can be adapted for subcutaneous implantation in animals, particularly mammals, to monitor body temperature and detect conditions such as fever, hypothermia, or overheating due to environmental changes. The sensor element can be designed for implantation under the skin, enabling continuous and non-invasive temperature monitoring.

[0208] The temperature sensor's high spatial resolution and sensitivity to temperature changes make it ideal for detecting subtle variations in body temperature that may indicate fever or other medical conditions. The temperature sensor can be integrated into medical devices such as wearable patches or embedded in medical equipment requiring precise patient temperature monitoring.

[0209] Furthermore, the temperature sensor's ability to be adjusted for its Coulomb barrier after irradiation ensures that it can be tailored to the specific temperature range relevant for medical diagnoses. This adjustment enables precise temperature measurements that are reliable and consistent, which is of paramount importance in medical settings where accurate temperature readings can influence treatment decisions.

[0210] The encapsulation of the sensor element and electrodes in a biocompatible cover layer ensures that the temperature sensor can be safely used in contact with the skin or implanted in the body without risk of adverse reactions. This protective layer also helps maintain the sensor's integrity during sterilization processes, ensuring it remains a sterile and safe medical device. By leveraging the temperature sensor's adaptability and precision, healthcare providers benefit from a tool that enhances patient care through the accurate and timely detection of temperature-related health issues.

[0211] In some versions, the temperature sensor can be specifically configured for use in fertility monitoring applications, such as determining ovulation in women for contraceptive purposes. The sensor element, when deposited on a biocompatible flexible substrate, can be designed to be worn close to the skin or even placed inside the body, enabling continuous and non-invasive monitoring of basal body temperature, a known indicator of ovulation.

[0212] The sensor element's high sensitivity to temperature changes makes it particularly suitable for detecting the slight temperature rise that accompanies ovulation. Through continuous monitoring and recording of temperature data, the sensor can help predict the fertile window and thus support natural family planning methods.

[0213] The adaptability and precision of the temperature sensor, combined with its compact size and integration into wearable or insertable devices, offer a discreet and convenient solution for women seeking a natural and non-invasive method of contraception. This application of the temperature sensor represents a valuable tool in the field of reproductive health and personal well-being.

[0214] In some versions, the temperature sensor can be adapted for use in neonatal intensive care units for the continuous monitoring of newborns' body temperature. When deposited on a biocompatible, flexible substrate, the sensor element can be designed to lie gently on the delicate skin of newborns, enabling non-invasive and continuous temperature monitoring.

[0215] The temperature sensor's high spatial resolution and sensitivity to temperature changes make it ideal for detecting minute variations in body temperature, which are of particular importance in neonatology. Newborns, especially premature infants, are unable to effectively regulate their body temperature, making them vulnerable to hypothermia and hyperthermia. Continuous temperature monitoring with the sensor can provide healthcare providers with real-time data to ensure that newborns are kept within the narrow temperature range that is safe and conducive to their health and development. By leveraging the sensor's adaptability and precision, neonatal care providers can benefit from a tool that improves patient care through the accurate and timely detection of temperature-related health issues in newborns.This application of the temperature sensor represents a valuable tool in the field of neonatal health and patient well-being.

[0216] In the energy industry, the temperature sensor can be integrated into batteries or battery arrays to monitor their temperature, providing valuable information for battery management systems. The temperature sensor can also be used in nuclear power plants to measure radiation, helping to ensure the plant's safety and efficiency.

[0217] In another version, the temperature sensor is used to determine the temperature of solar cells or batteries by being applied directly to the substrate of the solar module, directly to the housing, or even inside a battery. The sensor element can be designed to conform to the contours of the solar cell substrate or the complex shapes of battery housings, enabling precise and continuous temperature monitoring.

[0218] The sensor element's high spatial resolution and sensitivity to temperature changes make it ideal for detecting temperature gradients that can affect the efficiency and lifespan of solar cells and batteries. By continuously monitoring the temperature, the sensor can provide valuable data for optimizing the performance and safety of these energy systems.

[0219] By leveraging the adaptability and precision of the temperature sensor, manufacturers and operators of solar modules and batteries can benefit from a tool that improves the management and maintenance of these energy systems through the accurate and timely detection of temperature-related problems. This application of the temperature sensor represents a valuable tool in the field of renewable energy and energy storage solutions.

[0220] In another version, the temperature sensor is designed to withstand and measure high temperatures, making it suitable for applications in machinery, combustion engines, turbines, and other high-temperature environments. The sensor element can be engineered to withstand the extreme temperatures frequently encountered in industrial and mechanical settings. For example, the temperature sensor can also be used as a fire detector, as its small thermal mass allows it to respond to even small temperature changes, enabling the early detection of fires or smoldering embers. This sensitive temperature dependence allows for the prediction of fires before they even start.

[0221] The sensor element's robustness against high temperatures is achieved by selecting materials with high melting points and thermal stability during the manufacturing process. For example, the melting point of the sensor elements is 250°C, 300°C, 500°C, or higher. The sensor's ability to be post-processed to match its Coulomb barrier allows for precise adjustment of its temperature response to the high-temperature range experienced by machinery and motors. This adjustment ensures that the temperature sensor can deliver reliable and accurate measurements, which are crucial for monitoring thermal performance and preventing overheating in such demanding applications.

[0222] Furthermore, the encapsulation of the sensor element and electrodes in a high-temperature-resistant cover layer ensures that the sensor retains its functionality and integrity even under severe thermal stress. This protective layer also helps to protect the sensor from the harsh conditions prevalent in industrial environments, such as exposure to aggressive chemicals, abrasion, and mechanical stress.

[0223] By integrating the temperature sensor into the structural components of machines and motors, operators can gain real-time insights into the thermal dynamics of their systems. This information is invaluable for preventative maintenance, efficiency optimization, and ensuring the safety and longevity of the equipment. The temperature sensor's adaptability to high-temperature applications represents a transformative advancement in the field of industrial monitoring and control systems.

[0224] In the field of environmental monitoring, the temperature sensor can be used to measure temperature in various environments, from low-temperature scientific investigations to high-temperature industrial processes. Its ability to operate reliably in microwave and RF environments makes it suitable for use in diverse conditions. In the consumer goods industry, the temperature sensor can be integrated into various consumer products, from portable devices to household appliances, providing accurate and reliable temperature measurements for improved performance and user experience.

[0225] In some aspects, the temperature sensor can be used to measure the temperature in a solid-state thermal relay assembly. A solid-state thermal relay is an electronic switching device that turns on or off when a small external voltage is applied to its control terminals. The temperature sensor can detect temperature changes within the relay due to its temperature-dependent conductivity. This allows for a direct measurement of the temperature inside the relay, which can be useful for monitoring the relay's performance and identifying potential problems caused by overheating.

[0226] In summary, the temperature sensor disclosed here is not limited to use in the example applications described here, but can be useful in almost any application where precise temperature measurements are desired.

[0227] Figures 16A and 16B schematically depict a medical device 180 in which a temperature sensor 100 is integrated or on which a temperature sensor 100 is arranged. The medical device 180 is designed to perform thermal treatment procedures and can, for example, be the treatment head of a coagulator, an electrocautery device, a plasma coagulator, a plasma ablation instrument, a laser ablation instrument, or a resection instrument. The medical device 180 can, for example, be designed as a laparoscopic or other minimally invasive instrument, but can also have other form factors. The medical device can also be designed to perform open surgery. The representation in Figures 16A and 16B is to be understood schematically only and includes any medical device.

[0228] The exemplary medical device 180 comprises a treatment head 182, which is set up to carry out the respective thermal treatment procedure.

[0229] The treatment head 182 is connected to an elongated handle 184 or a holder for operation, for example by the surgeon. The temperature sensor 100 is integrated into the treatment head 182 or provided directly on it, so that it can measure either the temperature of the treatment head 182 itself or the temperature of its surroundings.

[0230] In Figure 16A, the temperature sensor 100 comprises a nanogranular sensor element 20, which, as described above, is positioned between electrodes 30. There is an electrode gap 36 between the electrodes 30, and the nanogranular sensor element 20 bridges this gap.

[0231] The electrodes 30 are each contacted with a connecting cable 38, the connecting cables 38 extending from the temperature sensor 100 through the style 184 to enable electrical connectivity and signal transmission.

[0232] Figure 16B shows the treatment head 182 in a schematic enlargement. The treatment head 182 comprises the temperature sensor 100 with the nanogranular sensor element 20 and the electrodes 30.

[0233] In some aspects, the temperature sensor 100 can be used to control or regulate the energy supplied to the treatment head 182, for example, the coagulator, electrocautery, plasma coagulator, plasma ablation instrument, laser ablation instrument, or resection instrument. This arrangement can enable precise temperature monitoring and adjustment during surgical procedures and potentially improve patient safety and the effectiveness of the medical device 180.

[0234] Figure 17 shows another embodiment of the medical device 180. In this configuration, the temperature sensor 100 in the treatment head 182 comprises a nanograin sensor element 20 positioned between an inner electrode pair 32 and an outer electrode pair 34. This arrangement can offer enhanced temperature measurement capabilities and compensation mechanisms. This embodiment of the temperature sensor 100 has also been described above, so a detailed description is omitted here.

[0235] In various implementations, the medical device 180 can be designed for minimally invasive procedures, with the temperature sensor 100 providing real-time temperature data. This data can be used to regulate the device's energy output, potentially preventing overheating of the surrounding tissue and improving surgical outcomes. The compact nature of the nanogranular sensor element 20 allows for integration into various types of medical devices without significantly altering their form factor or treatment functionality.

[0236] In some aspects, the nanogranular sensor element, due to its small size and unique electrical properties, can provide highly sensitive and precise temperature measurements. The nanoscale dimensions of the sensor element enable rapid response times to temperature changes, allowing for real-time monitoring in various applications and thus potentially increasing patient safety.

[0237] In some cases, rapid temperature sensing and control can also contribute to shorter procedure and operating times. By enabling quick adjustments and precise temperature control, the system can potentially achieve the desired cauterization or electroablation effect more efficiently and potentially reduce the overall duration of the procedures.

[0238] The ability to deposit the sensor element directly onto various substrate materials and shapes can improve versatility and integration capabilities. This feature allows the temperature sensor to be incorporated into a wide variety of devices and structures, including curved or flexible surfaces of medical devices.

[0239] The sensor element's adjustable Coulomb barrier, achieved through post-processing techniques, allows for customization of the temperature response for specific measurement ranges. This adaptability enables the sensor to be optimized for various applications and environmental conditions.

[0240] In some implementations, the sensor's compact size can minimize thermal mass, potentially reducing its impact on the temperature of the measured object or its environment. This characteristic can be particularly advantageous in applications requiring minimally invasive or minimally disruptive temperature sensing.

[0241] In some aspects, the described temperature sensor 100 can be integrated into a cryocatheter system as a medical device 180 to enable precise temperature monitoring and control during cryoablation procedures. The nanogranular sensor element can be positioned near the tip of the cryocatheter, allowing for accurate measurement of tissue temperatures during freezing. This integration can provide real-time feedback on the cooling process and potentially improve the safety and efficacy of cryoablation treatments.

[0242] The compact size and adaptability of the Temperature Sensor 100 allow for seamless integration into the cryocatheter design without significantly altering its form factor or flexibility. Multiple sensor elements can be positioned along the length of the catheter to provide a temperature profile during the procedure.

[0243] In some implementations, the sensor's temperature data can be used for regulation or control to control the flow of the cryogenic fluid, thus maintaining optimal freezing temperatures and preventing excessive cooling of the surrounding healthy tissue. The rapid response time of the nanogranular sensor element allows for quick adjustments to the cooling process, improving the precision of the cryoablation procedure.

[0244] In some aspects, the rapid response time and low thermal mass of the Temperature Sensor 100 can enable particularly fast monitoring during cryoablation procedures. This rapid responsiveness can lead to increased reliability for the patient and help reduce the risk of injury to surrounding tissue.

[0245] In some cases, rapid temperature sensing and control can also contribute to shorter procedure and operating times. By enabling quick adjustments and precise temperature control, the system can potentially achieve the desired freezing effect more efficiently and shorten the overall duration of the cryoablation procedure.

[0246] In some aspects, the style 184 of the medical device 180 can internally accommodate one to four or more connecting cables 38 to allow the wiring and contacting of the various temperature sensors 100 proposed above. Depending on the application, between one and four temperature sensors or a larger number of temperature sensors may be provided.

[0247] In some aspects, the internal resistance of the nanogranular sensor element 20 can be set so high that the use of very thin connecting cables becomes possible without significantly changing the measured resistance.

[0248] In some aspects, the nanogranular sensor element, through the manufacturing steps described above, can exhibit a quasi-linear resistance behavior in the temperature range of 30° to 80°C. This resistance behavior is particularly nearly linear compared to known NTCs. This linear response enables precise and reliable temperature measurements within this range, which is relevant for surgical applications.

[0249] The consistent performance of the nanogranular sensor element across this temperature range can also contribute to the overall reliability of the medical device. This reliability can be crucial for ensuring patient safety during procedures. Where applicable, all individual features illustrated in the exemplary embodiments can be combined and / or interchanged without departing from the scope of the invention.

[0250] List of reference signs

[0251] 10 insulating substrate

[0252] 12 non-insulating substrate

[0253] 14 flexible substrate

[0254] 16 outer functional layer(s)

[0255] 20 nanogranular sensor element

[0256] 22 Reference sensor element

[0257] 30 electrode

[0258] 32 first pair of electrodes

[0259] 34 second pair of electrodes

[0260] 36 Gap between the electrodes

[0261] 38 connection cables

[0262] 40 Cover layer

[0263] 60 Insulation layer

[0264] 70 Voltmeter

[0265] 72 Constant current source

[0266] 74 Constant voltage source

[0267] 76 conventional ohmic resistance

[0268] 700 bridge circuit

[0269] 100 temperature sensor

[0270] 110 passive thermocouple

[0271] 120 temperature sensor

[0272] 130 high-precision temperature sensors

[0273] 140 high-precision temperature sensors

[0274] 150 temperature probe

[0275] 160 flexible printed circuit board, 170 pins of a connector

[0276] 180 medical devices

[0277] 182 Treatment head of the medical device

[0278] 184 Style of medical device R1, R2, R3, R4 resistors in the Wheatstone bridge

Claims

Claims 1. Temperature sensor (100, 110, 120, 130, 140, 150, 160, 170), comprising: a substrate (10, 12, 14); a nanogranular sensor element (20) deposited on the substrate (10, 12, 14); at least two electrodes (30, 12) electrically connected to the sensor element (20) to enable the measurement of temperature-dependent conductivity changes of the sensor element (20).

2. Temperature sensor according to claim 1, characterized in that the width of the sensor element (20) is between 1 nm and 20 µm, preferably between 5 nm and 400 nm, for example 300 nm, particularly preferably between 8 nm and 12 nm, and / or the height of the sensor element (20) is between 1 nm and 3 pm, preferably 5 nm to 400 nm, for example 300 nm or µm, and / or the length of the sensor element (20) is between 1 nm and 20 pm, preferably between 5 nm and 400 nm, for example 300 nm, particularly preferably between 8 nm and 12 nm.

3. Temperature sensor according to claim 1 or 2, characterized in that the mass of the sensor element (20) is between 1x10 -24 kg and 1x10 -18 kg, preferably between 5x10 -21 kg and 1x10 -18 kg.

4. Temperature sensor according to one of the preceding claims, characterized in that the thermal response time of a nanogranular sensor element (20) is less than 600x10 -9 s is, preferably smaller than 6x10 -9 s is, especially preferred, smaller than 6x10 -12 s is.

5. Temperature sensor according to one of the preceding claims, characterized in that the sensor element (20) is in direct contact with the substrate (10, 12, 14).

6. Temperature sensor according to one of the preceding claims, characterized in that the sensor element (20) is encapsulated with a covering layer (40).

7. Temperature sensor according to claim 6, characterized in that - the covering layer (40) is a thermal and / or chemical barrier and / or - the covering layer (40) has a height between 1 nm and 3 pm, preferably a height between 25 nm and 400 nm, wherein the height of the covering layer is preferably equal to or greater than the tallest structure applied to the substrate.

8. Temperature sensor according to one of the preceding claims, characterized in that the substrate (10, 14) is electrically insulating, wherein the substrate (10, 12, 14) preferably consists of a polymer or a ceramic or comprises a polymer and a ceramic.

9. Temperature sensor according to one of the preceding claims, characterized in that the substrate (12, 14) is electrically non-insulating, wherein the substrate (12, 14) preferably consists of a metal or a semiconductor or comprises a metal or a semiconductor.

10. Temperature sensor according to claim 9, characterized in that the sensor element (20) is in direct contact with the substrate (12, 14), wherein an insulating layer (60) is arranged between a first electrode (30) and the substrate (12, 14) and wherein the electrically non-insulating substrate (12, 14) preferably forms a second electrode (30).

11. Temperature sensor according to one of the preceding claims, characterized in that the substrate (10, 12, 14) is mechanically flexible.

12. Temperature sensor according to one of the preceding claims, characterized in that the electrodes (30) are arranged on both sides of the sensor element (20).

13. Temperature sensor according to one of the preceding claims, characterized in that the electrodes (30) are arranged above and below the sensor element (20).

14. Temperature sensor according to one of the preceding claims, characterized by four electrodes (30), wherein the four electrodes (30) overlap section by section with the sensor element (20), - wherein the length of the sensor element (20) is greater than the greatest distance between the contact surfaces of the electrodes (30) and the sensor element (20), or - wherein the length of the sensor element (20) corresponds to the greatest distance between the contact surfaces of the electrodes (30) and the sensor element (20), or - wherein the length of the sensor element (20) is less than the greatest distance between the contact surfaces of the electrodes (30) and the sensor element (20).

15. Temperature sensor according to one of the preceding claims, characterized by a Bridge circuit (700), wherein at least one sensor element (20) is a measuring resistor.

16. Temperature sensor according to the preceding claim, characterized in that the Bridge circuit (700) is a 1 / 4 bridge, a 1 / 2 bridge or a 4 / 4 bridge.

17. Method for manufacturing a temperature sensor (100, 110, 120, 130, 140, 150, 160, 170), the method comprising: Providing a substrate (10, 12, 14); Providing at least two electrodes (30) Deposition of a nanogranular sensor element (20) on the substrate (10, 12, 14); and connection of the sensor element (20) to the at least two electrodes (30) to enable the measurement of temperature-dependent conductivity changes of the sensor element (20).

18. Method according to claim 17, characterized in that the step of depositing the sensor element (20) comprises the following steps: Masking the deposition site for the sensor element (20); Deposition of the sensor element using pulsed laser deposition and / or laser evaporation and / or cluster deposition and / or sputtering and / or co-sputtering; and removal of the masking.

19. Method according to claim 17, characterized in that the step of depositing the sensor element (20) comprises the following steps: Local deposition of the sensor element (20) by means of Electron Beam Induced Deposition (EBID) or Focused Ion Beam Deposition.

20. Method according to one of claims 17 to 19, characterized in that the deposited sensor element (20) is post-processed, preferably by changing the crystal structure and / or grain structure, wherein the temperature with the maximum conductivity change is particularly preferably shifted into a temperature measurement range.

21. Method according to claim 20, characterized in that the post-processing includes or is annealing, in particular local laser annealing.

22. Method according to one of claims 17 to 21, characterized in that the step of providing the electrodes (30) also includes the step of providing an insulating layer (60).

23. Method according to any one of claims 17 to 22, characterized by a step of providing a covering layer (40).

24. Medical instrument (180) comprising: a treatment head (182) for treating a patient; and a temperature sensor (100) arranged on the treatment head (182) according to any one of claims 1 to 16.

25. Medical instrument (180) according to claim 24, characterized in that the nanogranular sensor element (20) is deposited directly on the treatment head (182) as a substrate.

26. Medical instrument (180) according to claim 24 or 25, characterized in that the treatment head (182) is configured for carrying out a thermal treatment procedure, preferably for carrying out a laparoscopic thermal treatment procedure.

27. Medical instrument (180) according to claim 26, characterized in that the treatment head (182) is the treatment head of a coagulator, an electrocautery, a plasma coagulator, a plasma ablation instrument, a laser ablation instrument, or a resection instrument.

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