Apparatus for propelling and manipulating microstructures

Abstract

The device (1) comprises: a propulsion element (2) having at least one portion (20) connecting a front portion (21) and a rear portion (23) which is deformable by extension / contraction along a main axis (X2); at least two guiding elements (3, 5, 7) which, under the action of energy input, can cause the propulsion element (2) to rotate around a first rotation axis and a second rotation axis, respectively, the first rotation axis and the second rotation axis being transverse to each other and to the main axis (X2) of the propulsion element; a control unit (9) which is configured to actuate the rotation of the propulsion element (2) around at least one axis transverse to the main axis (X2) in a manner coordinated with the extension / contraction deformation of the deformable portion (20) of the propulsion element (2) along the main axis (X2).

Description

Technical Field

[0001] This invention relates to a device for propelling and manipulating microstructures (e.g., mobile flexible tubes such as stents or catheters) or microrobots, designed to move in fluids, particularly in the blood vessels (such as arteries or veins) of a subject, or within the organs (such as the brain, heart, liver, pancreas, etc.) of a subject. Especially in the context of minimally invasive surgery or targeted therapy, the mobile flexible tubes or microrobots can be used to perform a variety of biomedical procedures. Background Technology

[0002] Reaching deep and functional structures without causing any damage is a major challenge in minimally invasive surgery, especially in neurosurgery. Thanks to microtechnology, it has become possible to deliver fully autonomous micro-medical devices into the blood vessels or organs of a patient. Nevertheless, such micro-medical devices require a system capable of propulsion and manipulation in three dimensions with at least the precision equivalent to the device's size, even in heterogeneous and sensitive environments.

[0003] In this context, the object of the present invention is to provide a device for propulsing and manipulating microstructures such as flexible tubes or microrobots, which ensures effective and reliable propulsion and manipulation of the microstructures (including in fluid environments with low Reynolds numbers), with an accuracy at least equivalent to the size of the microstructure, while maintaining as much integrity as possible the environment in which the microstructure moves. Summary of the Invention

[0004] Therefore, one object of the present invention is a device for propelling and manipulating microstructures such as flexible tubes or microrobots, the device comprising:

[0005] - A propulsion element comprising at least one portion capable of elongating / contracting along a main axis, connecting a front portion and a rear portion of the propulsion element;

[0006] - At least two guiding elements adapted to cause a propulsion element to rotate about a first rotation axis and a second rotation axis respectively, which are transverse to each other and transverse to the main axis of the propulsion element, under the action of energy supply through a corresponding connection with an energy source;

[0007] - A control unit configured to actuate the rotation of the propulsion element about at least one axis transverse to the main axis by selectively controlling one or more of the connections to the energy source in a manner that engages with the elongation / contraction deformation of the deformable portion of the propulsion element along the main axis. The guiding element also includes at least two guiding segments based on an active material, which are reversibly deformable under the action of energy supply through the corresponding connections to the energy source. Each guiding segment is adapted to cause the propulsion element to rotate about a rotation axis transverse to the main axis of the propulsion element under the action of energy supply through its deformation.

[0008] The propulsion and manipulation device according to the invention allows for the manipulation of microstructures in three dimensions due to the possibility of actuating the propulsion element about at least two rotation axes in a manner that cooperates with the propulsion of the microstructure obtained by the deformation of the deformable portion of the propulsion element. These rotation axes are transverse to each other and transverse to the main axis. In the context of the invention, the two axes are transverse to each other when they are not parallel, including but not limited to the case where the two axes are perpendicular to each other.

[0009] In the context of this invention, rotational actuation is performed, particularly simultaneously or sequentially, in coordination with the deformation of the deformable portion of the propulsion element, in order to obtain the desired movement and trajectory of the microstructure within an environment, particularly a fluid environment with a low Reynolds number. More specifically, rotational actuation can be performed simultaneously with the deformation of the deformable portion of the propulsion element, or sequentially with the deformation of the deformable portion of the propulsion element, such that rotation and deformation are performed one after another, particularly in a repetitive manner.

[0010] In the context of this invention, microstructures equipped with propulsion and manipulation devices according to the invention typically have an outer diameter of less than or equal to 5 mm, particularly less than or equal to 2 mm or 1 mm.

[0011] According to one feature, the propulsion element includes at least a first guide segment and a second guide segment, such that deformation of the first guide segment causes the propulsion element to rotate about a first rotation axis perpendicular to the main axis of the propulsion element, and deformation of the second guide segment causes the propulsion element to rotate about a second rotation axis perpendicular to both the main axis of the propulsion element and the first rotation axis.

[0012] According to one embodiment of the guide section, the section is a region of the deformable portion of the propulsion element coated with an active material. According to another embodiment of the guide section, the section includes a support member provided with active material, which is attached to the deformable portion of the propulsion element.

[0013] According to one embodiment, the deformable portion of the propulsion element is made of a material with a Young's modulus of 0.1 to 10 GPa, preferably 0.5 to 2 GPa. In one embodiment, the front portion, rear portion, and deformable portion of the propulsion element are all made of the same material. In one embodiment, the constituent materials of the front portion, rear portion, and deformable portion are biocompatible polymers. Examples of suitable materials for the front portion, rear portion, and / or deformable portion are UV-curable mixed inorganic-organic polymers, such as ORMOCLEAR, a product manufactured by MICRO RESIST TECHNOLOGY GmbH.

[0014] In one embodiment, at least one guide segment comprises an electroactive material or a bimetallic element, and the propulsion and actuation device comprises an electrical energy source connected to the guide segment to activate its deformation. Specifically, the energy source is a power supply connected to the electroactive material or bimetallic element of the guide segment via wires or cables.

[0015] In the context of this invention, electroactive materials are materials that deform under the influence of electrical energy, particularly by changing their shape or size. Examples of suitable electroactive materials in the context of this invention include shape memory alloys (such as nitinol); or electroactive polymers (EAPs), particularly dielectric and ionicly active polymers. As a non-limiting example, an ionicly active polymer that can be used in the context of this invention is poly(3,4-ethylenedioxythiophene) (PEDOT).

[0016] In the context of this invention, a bimetallic element is an element comprising two materials that, under the influence of heat generated by an electric current when the materials are conductive, elastically deform independently according to their different mechanical properties. This deformation, caused by the solid contact of the two materials, results in a very significant deformation of the bimetallic element. Such a bimetallic element can be formed, in particular, by co-rolling two metal strips. Suitable examples of bimetallic elements in the context of this invention are copper and steel bimetals, or iron and nickel bimetals, because these bimetals combine metallic materials with completely different coefficients of thermal expansion.

[0017] In one embodiment, at least one guide segment comprises a photoactive material, and the propulsion and maneuvering device comprises a radiation source that emits radiation opposite the guide segment to activate its deformation. In particular, the radiation source is a laser source or an LED (light-emitting diode) that transmits its radiation upward to the photoactive material of the guide segment using an optical fiber having a distal end positioned relative to the photoactive material of the guide segment.

[0018] In the context of this invention, photoactive materials are materials that deform under radiation, particularly under the influence of light energy. Examples of suitable photoactive materials in the context of this invention include liquid crystal networks comprising azobenzene molecules. The radiation source can be a white light source encompassing all wavelengths of the visible spectrum. As a non-limiting example, a photoactive material usable in the context of this invention is an actuator based on a dual-photosensitive liquid crystal, which in particular contains an azocyanine dye locally converted to the form of hydroxyazopyridinium through acid treatment.

[0019] According to one feature, at least two of the guide segments are configured such that, when the at least two guide segments deform simultaneously, the deformable portion of the propulsion element undergoes elongation / contraction deformation along the main axis, and when the at least two guide segments selectively deform, the propulsion element rotates about a rotation axis transverse to the main axis. By selectively supplying energy to the guide segments, the rotation and elongation / contraction deformation of the propulsion element can then be actuated, allowing for the directional manipulation and propulsion of the microstructure.

[0020] Based on one characteristic, the guide segments are isotropically distributed around the main axis of the propulsion element. This leads to improved control over the directional manipulation of the propulsion element.

[0021] According to one embodiment, the deformable portion of the propulsion element includes a single flexible leg that is helically disposed between the front and rear portions of the propulsion element about a main axis. The flexible leg includes at least two guide segments that are distributed along the flexible leg and configured to cause the propulsion element to rotate about a first rotation axis and a second rotation axis, respectively, by deformation of the guide segments. The first rotation axis and the second rotation axis are transverse to each other and transverse to the main axis of the propulsion element.

[0022] According to another embodiment, the deformable portion of the propulsion element includes at least two flexible legs that are helically disposed between the front and rear portions of the propulsion element about a main axis. The propulsion and actuation device includes at least a pair of guide segments on the first and second flexible legs, respectively. The at least one pair of guide segments is configured to cause the propulsion element to rotate about a first and a second rotation axis, respectively, by deformation of the guide segments. The first and second rotation axes are transverse to each other and transverse to the main axis of the propulsion element.

[0023] According to one aspect of the invention, the guiding element includes at least two electromagnetic guiding coils, each of which is provided with a corresponding connection to an electrical energy source and forms an electromagnetic transducer with a magnet fixed to the propulsion element. The magnet is substantially parallel to the main axis of the propulsion element in a rest position. Each guiding coil is adapted to cause the magnet to rotate relative to its rest position under the action of an electrical energy supply, thereby causing the propulsion element to rotate about a rotation axis transverse to the main axis of the propulsion element.

[0024] According to one characteristic, for each electromagnetic transducer comprising a magnet fixed to the propulsion element and a guide coil, the magnet is inserted into the guide coil to actuate the rotation of the propulsion element. This arrangement ensures electromagnetic conversion efficiency, thereby allowing reliable and accurate control of the propulsion element's rotation via electrical connections acting on each guide coil. Of course, the polarity of the magnet is matched to the power supply of each guide coil to achieve the desired rotation of the propulsion element.

[0025] According to one embodiment, the propulsion and manipulation device further includes a linear actuation electromagnetic coil, which is provided with a corresponding connection to an electrical energy source and also forms an electromagnetic transducer with a magnet fixed to the propulsion element. The linear actuation coil is adapted to cause translation of the magnet parallel to the main axis under the action of electrical power, thereby causing elongation / contraction deformation of the deformable portion of the propulsion element along the main axis. By selectively powering the guide coil and the linear actuation coil, rotation and elongation / contraction deformation of the propulsion element can then be actuated, allowing for ensuring the directional manipulation and propulsion of the microstructure.

[0026] According to another embodiment, at least two of the electromagnetic guide coils are configured such that when the at least two electromagnetic guide coils are simultaneously powered, they actuate the deformable portion of the propulsion element to elongate / contract along the main axis, and when the at least two electromagnetic guide coils are selectively powered, they cause the magnet to rotate relative to its resting position, thereby causing the propulsion element to rotate about a rotation axis transverse to the main axis. By selectively (e.g., simultaneously or continuously) powering the guide coils, the rotation and elongation / contraction of the propulsion element can be actuated, which allows for ensuring the directional manipulation and propulsion of the microstructure.

[0027] According to one embodiment, the central axis of each guide coil is substantially parallel to the main axis of the propulsion element. According to another embodiment, the central axis of each guide coil is substantially perpendicular to the main axis of the propulsion element.

[0028] The number of guide coils can be any number greater than or equal to two. In particular, in a non-limiting manner, within the context of this invention, the following arrangements can be considered: two guide coils arranged sequentially along the main axis of the propulsion element, their central axes being substantially parallel to and not coinciding with the main axis; two guides arranged side by side, their central axes being substantially parallel to the main axis of the propulsion element; at least three guide coils, especially three, four, five, or six guide coils, arranged sequentially along the main axis of the propulsion element, their central axes being substantially parallel to and not coinciding with the main axis; at least three guide coils, especially three, four, five, or six guide coils distributed around the main axis of the propulsion element, their central axes being substantially parallel to the main axis of the propulsion element; at least three guide coils, especially three, four, five, or six guide coils distributed around the main axis of the propulsion element, their central axes being substantially perpendicular to the main axis of the propulsion element.

[0029] According to one feature, the control unit is also configured to actuate the elongation / contraction deformation of the deformable portion of the propulsion element along the main axis. Therefore, the actuation of the rotation of the propulsion element and the actuation of its elongation / contraction deformation can be optimally coordinated.

[0030] According to one feature, the propulsion and maneuvering device includes a linear actuator configured to actuate elongation / contraction deformation of a deformable portion of the propulsion element along a main axis. According to one embodiment, the linear actuator includes an electromagnetic transducer comprising a combination of an electromagnetic coil fixed to one end of the deformable portion and a permanent magnet fixed to the other end of the deformable portion. According to one embodiment, the linear actuator includes a pump. This embodiment is suitable for situations where the deformable portion of the propulsion element may contain fluid within its internal space, particularly suitable for situations where the deformable portion has an envelope forming a continuous outer peripheral wall. In one embodiment, the deformable portion of the propulsion element includes a bellows and the actuator includes a pump.

[0031] In one embodiment, the propulsion and manipulation device includes at least one propulsion cilia fixed to a front portion of the propulsion element, one end of the propulsion cilia being fixed to the front portion, while the other end of the propulsion cilia is configured as a free end, which is free to move to induce microstructures, particularly at a depth of 10. -5 Up to 10 -1 Non-reciprocating motion in low Reynolds number fluids. Due to the presence of these cilia, propulsive motion of microstructures is achieved even in viscous or viscoelastic materials, especially in the organs of the subject (such as the brain). The continuous elongation / contraction cycle of the deformable portion of the propulsive element causes the propulsive cilia to move in the viscous or viscoelastic material, thereby generating a net propulsive force due to the interaction between the propulsive cilia and the viscous or viscoelastic material.

[0032] According to one characteristic, for each elongation / contraction deformation cycle along its main axis of the deformable portion of the propulsion element, the propulsion cilia or the free end of each propulsion cilia in the contraction phase of the propulsion element have 10 -5 Up to 10 -1 The path in a low Reynolds number fluid differs from the path of the propulsion cilia or the free end of each propulsion cilia in the fluid during the elongation phase of the propulsion element. This implementation of the elongation and contraction phases of the propulsion cilia relative to the deformable portion allows for non-reciprocating motion of the microstructure, which enables efficient movement in fluids with low Reynolds numbers.

[0033] In particular, in a non-limiting embodiment, the path of one or more propelling cilia's free ends in a viscous or viscoelastic material is topologically equivalent to an elliptical or circular path for each elongation / contraction cycle of the deformable portion. It should be noted that paths where the free ends are topologically equivalent to line segments are not suitable for obtaining non-reciprocating motions of microstructures, even if different dynamics are applied along the path.

[0034] According to one embodiment, the rear portion of the propulsion element includes at least one propulsion cilia. In the context of this invention, it should be understood that the presence of propulsion cilia only in the front portion of the propulsion element is sufficient. However, the arrangement of propulsion cilia also on the rear portion can facilitate the propulsion of the microstructure in viscous or viscoelastic materials. According to one embodiment, when the rear portion of the propulsion element includes at least one propulsion cilia on its surface, the propulsion cilia of the rear portion, or each propulsion cilia, may be the same as or different from one or more propulsion cilia of the front portion of the propulsion element.

[0035] According to one embodiment, the propulsion cilia, or each propulsion cilia, of the front and / or rear portions of the propulsion element are made of a material with a Young's modulus of 0.1 to 10 GPa, preferably 0.5 to 2 GPa. According to one embodiment, the propulsion cilia, or each propulsion cilia, are made of the same material as the deformable portion of the propulsion element. In one embodiment, the material of the propulsion cilia is a biocompatible polymer. Examples of suitable materials for the propulsion cilia include polydimethylsiloxane (PDMS), silicon, or UV-curable mixed inorganic-organic polymers (such as ORMOCLEAR).

[0036] According to one embodiment, at least two guide elements are radially positioned outside the deformable portion.

[0037] According to one embodiment, the deformable portion includes an oscillating disk disposed between the front portion and the rear portion, and at least two guide elements are disposed between the rear portion and the oscillating disk.

[0038] According to one embodiment, the propulsion and manipulation device includes at least two propulsion elements arranged sequentially, and the control unit is configured to actuate the propulsion elements in a predefined time sequence, causing elongation / contraction deformation cycles along their main axis, in order to induce microstructures, particularly those with a diameter of 10... -5 Up to 10 -1 Non-reciprocating motion in fluids with low Reynolds numbers. This arrangement is another way to obtain non-reciprocating motion of microstructures, thereby allowing efficient movement in fluids with low Reynolds numbers. This arrangement can be used alone or in combination with at least one propulsion cilia to induce the non-reciprocating motion described above.

[0039] Another object of the present invention is a microstructure comprising the propulsion and manipulation device as described above. According to one aspect of the invention, the microstructure is configured to move in a fluid material having a low Reynolds number, particularly at a Reynolds number Re of 10. -5 Up to 10 -1 The Reynolds number Re is a dimensionless quantity that quantifies the relative magnitudes of inertial and viscous forces under given flow conditions. The Reynolds number Re can be expressed as the ratio of inertial forces to viscous forces in a fluid: Where u is the average velocity of the fluid relative to the object, L is the characteristic linear dimension, and ν is the kinematic viscosity of the fluid.

[0040] Another object of the present invention is a method for propulsing and manipulating microstructures such as flexible tubes or microrobots, the microstructures including propulsion and manipulation devices as described above, the method comprising the following steps:

[0041] - Introducing microstructures, including propulsion and manipulation devices, into systems with a particularly high density of 10 -5 Up to 10 -1 In fluids with low Reynolds numbers;

[0042] - By selectively controlling one or more of the connectors to the energy source using a control unit, the propulsion element is actuated about at least one axis transverse to the main axis of the propulsion element in a manner that cooperates with the elongation / contraction deformation of the deformable portion of the propulsion element along the main axis. Attached Figure Description

[0043] The features and advantages of the present invention will appear in the following description of several embodiments of the apparatus and method for propulsing and manipulating microstructures according to the present invention, which are provided by way of example only and with reference to the accompanying drawings, wherein:

[0044] - Figure 1The diagram shows a schematic cross-section of a microrobot including a propulsion and manipulation device according to a first embodiment of the present invention. The propulsion and manipulation device has a propulsion element in the form of a helical spring, the helical spring having three flexible legs, each flexible leg including a guide segment based on an electroactive material, the guide segment being provided with a corresponding electrical connection.

[0045] - Figure 2 It is similar to Figure 1 The cross-section shows the activation of the rotational motion of the microrobot;

[0046] - Figure 3 yes Figure 1 and Figure 2 A magnified partial 3D view of the propulsion element of a microrobot;

[0047] - Figure 4 It is similar to Figure 2 The cross-section of a microrobot including a propulsion and manipulation device according to a second embodiment of the present invention, the propulsion and manipulation device having a propulsion element in the form of a helical spring having three flexible legs, each flexible leg including a guide segment based on a photoactive material associated with an optical fiber transmitting the corresponding radiation;

[0048] - Figure 5 It is similar to Figure 2 The cross-section of a microrobot including a propulsion and manipulation device according to a third embodiment of the present invention has a propulsion element in the form of a helical spring having two flexible legs, each flexible leg including a plurality of guide segments based on an electroactive material, wherein each guide segment of each flexible leg is provided with a corresponding electrical connection so as to be independently powered by a power source;

[0049] - Figure 6 It is similar to Figure 2 The cross-section of a microrobot including a propulsion and manipulation device according to a fourth embodiment of the present invention, the propulsion and manipulation device having a propulsion element in the form of a helical spring having a single flexible leg, the flexible leg including a plurality of guide segments based on an electroactive material, wherein each guide segment of the flexible leg is provided with a corresponding electrical connection so as to be independently powered by a power source;

[0050] - Figure 7 It is similar to Figure 2 The cross-section of a microrobot including a propulsion and manipulation device according to a fifth embodiment of the present invention, the propulsion and manipulation device having two propulsion elements arranged sequentially, the control unit being configured to actuate the propulsion elements in an elongation / contraction deformation cycle along their main axis according to a predefined time sequence, so as to induce non-reciprocating motion of the microstructure;

[0051] - Figure 8 It is similar to Figure 1 The cross-section of a microrobot including a propulsion and manipulation device according to a sixth embodiment of the present invention, the propulsion and manipulation device having a propulsion element in the form of a helical spring having three flexible legs and an electromagnetic transducer having three coils, including a linear actuation coil and two rotary guide coils, each of which is provided with a corresponding electrical connection.

[0052] - Figure 9 It is similar to Figure 8 The cross-section shows the activation of the rotational motion of the microrobot;

[0053] - Figure 10 yes Figure 8 and Figure 9 A magnified stereoscopic view of a portion of the propulsion element of a microrobot;

[0054] - Figure 11 It is similar to Figure 10 A perspective view of a portion of the propulsion element of a microrobot including a propulsion and manipulation device according to a seventh embodiment of the present invention;

[0055] - Figure 12 It is similar to Figure 10 A perspective view of a portion of the propulsion element of a microrobot including a propulsion and manipulation device according to an eighth embodiment of the present invention;

[0056] - Figure 13 It is similar to Figure 3 A partial perspective view of the propulsion element of a microrobot including a propulsion and manipulation device according to a ninth embodiment of the present invention;

[0057] - Figure 14 It is similar to Figure 13 A partial perspective view of the propulsion element of a microrobot including a propulsion and manipulation device according to the tenth embodiment of the present invention;

[0058] - Figure 15 It is similar to Figure 13 A partial perspective view of the propulsion element of a microrobot including a propulsion and manipulation device according to the eleventh embodiment of the present invention;

[0059] - Figure 16 It is similar to Figure 15 However, a partial perspective view of the same embodiment of the present invention in action. Detailed Implementation

[0060] exist Figures 1 to 3In the first embodiment shown, the microrobot 10 is configured to move in a viscous or viscoelastic material (e.g., in the cerebrospinal fluid or extracellular matrix of the subject's brain), which, for the microrobot, is a fluid material with a low Reynolds number.

[0061] The microrobot 10 includes a propulsion and manipulation device 1 according to the invention, to which an active part 11 of the microrobot is fastened. The active part may be, for example, a sensor; an actuator; a container adapted to release a drug; etc.

[0062] like Figure 1 and Figure 2 As clearly shown, the propulsion and manipulation device 1 includes a propulsion element 2 comprising a front portion 21, a rear portion 23, and a deformable portion 20 connecting the front portion 21 and the rear portion 23. In this first embodiment, the deformable portion 20 is a helical spring capable of stretching / contracting along the main axis X2 of the propulsion element 2. The main axis X2 of the propulsion element 2 is defined herein as the central axis of the deformable portion 20, which is substantially perpendicular to the plane of the distal end plate 230 to which the deformable portion 20 is fastened.

[0063] The helical spring forming the deformable portion 20 includes three flexible legs 22, 24, and 26, which are helically arranged between the front portion 21 and the rear portion 23 of the propulsion element around the main axis X2. Each flexible leg 22, 24, and 26 has a corresponding guide segment 3, 5, and 7 based on an electroactive material (e.g., PEDOT ionic electroactive polymer). Each of the three guide segments 3, 5, and 7 can reversibly deform under the action of electrical power and is connected to a power source 8 via corresponding cables 83, 85, and 87.

[0064] Each guide segment 3, 5, 7 is adapted to cause deformation of the corresponding flexible leg and rotation of the propulsion element 2 through its deformation when powered by electricity. For each guide segment 3, 5, 7, the axis of rotation caused by the deformation of the guide segment is transverse to the main axis X2 of the propulsion element and transverse to the axis of rotation caused by the deformation of each of the other two guide segments. Figure 3 The enlarged view clearly shows that guide segments 3, 5, and 7 are isotropically distributed around the main axis X2 of the propulsion element 2, which allows for optimized directional control of the propulsion element. Therefore, in this invention, guide segments 3, 5, and 7, together with flexible legs 22, 24, and 26, form a unique multi-purpose functional group ensuring rotation and propulsion. This invention is not characterized by any coupling between different elements, each ensuring a different function.

[0065] The propulsion and manipulation device 1 also includes a linear actuator 4 configured to sequentially actuate the extension / contraction cycle of the deformable portion 20 of the propulsion element 2. The actuator 4 is an electromagnetic transducer comprising a permanent magnet 41 and an electromagnetic coil 42. The magnet 41 is fastened to the front portion 21 of the propulsion element 2 at the front end of the deformable portion 20, while the coil 42 is mounted on the rear portion 23, thereby fastening it to the rear end of the deformable portion 20. Depending on the current applied to the coil 42, the magnet 41 approaches or moves away from the coil 42, causing the deformable portion 20 to contract or extend.

[0066] like Figure 1 and Figure 2 As shown, the front portion 21 of the propulsion element 2 includes a plurality of propulsion cilia 28 on its surface, which are configured to interact with the material in which the microrobot 10 moves. The sequential elongation / contraction cycle of the deformable portion 20 actuated by the electromagnetic transducer 4 causes the propulsion cilia 28 to move in the material, thereby generating a propulsion force that causes the microrobot 10 to move.

[0067] For each elongation / contraction cycle of the deformable portion 20 actuated by the electromagnetic transducer 4, each propulsion ciliary 28 is configured such that the path of the free end 29 of the propulsion ciliary 28 in the viscous or viscoelastic material during the contraction phase of the deformable portion 20 differs from the path of the free end 29 in the viscous or viscoelastic material during the elongation phase of the deformable portion 20. Advantageously, the path of the free end 29 of the propulsion ciliary 28 in the viscous or viscoelastic material is topologically equivalent to the elliptical or circular path of each elongation / contraction cycle. This results in non-reciprocating motion of the microrobot 10, allowing it to move efficiently in fluid materials with low Reynolds numbers, such as cerebrospinal fluid or extracellular matrix.

[0068] The propulsion and manipulation device 1 also includes a control unit 9 configured to actuate the propulsion element 2 about at least one axis transverse to the main axis X2 by selectively controlling one or more of the electrical connections 83, 85, and 87. The control unit 9 is also configured to actuate the elongation / contraction deformation of the deformable portion 20 along the main axis X2. Therefore, the actuation of the rotation of the propulsion element 2 and the actuation of the elongation / contraction deformation of the deformable portion 20 along the main axis X2 can be optimally coordinated to achieve the desired movement and trajectory of the microrobot 10 within the material. The control unit 9 thus actuates the individual element (propulsion element 2) and allows the actuation of this individual element to cause propulsion and rotation of the device 1.

[0069] A type of device used in applications with, in particular, 10 -5 Up to 10 -1A method for propulsing and manipulating a microrobot 10 in a low Reynolds number fluid, the method comprising using a control unit 9 to selectively control one or more of electrical connectors 83, 85, 87 to actuate a propulsion element 2 about at least one axis transverse to the main axis X2 in a manner that engages, either simultaneously or sequentially, with the elongation / contraction deformation of the deformable portion 20 along the main axis X2.

[0070] As a non-limiting example, a microrobot 10 exhibits good propulsion and guidance performance in fluid materials with low Reynolds numbers, possessing the following characteristics:

[0071] -Total length of the microrobot 10: 2mm;

[0072] - Diameter of the microrobot 10: 2mm;

[0073] - The length of the deformable portion 20 of the propulsion element 2: 0.5 mm;

[0074] - Length of linear actuation coil 42: 0.5mm;

[0075] - Length of magnet 41: 0.8mm;

[0076] - Cross-section of each propulsing ciliary 28: 2500μm 2 .

[0077] Manufacturing process

[0078] The front portion 21, rear portion 23, and deformable portion 20 are fabricated in one piece using a UV-curable hybrid inorganic-organic ORMOCLEAR polymer as photoresist via 3D laser lithography. The photoresist is applied to a glass substrate, and a point laser selectively cures the photoresist according to a 3D CAD design. Advancing cilia 28 are fabricated in one piece with the front portion 21, i.e., made of the same material as the front portion 21. Guide segments 3, 5, and 7 are obtained by depositing a layer of PEDOT ionically active polymer on each of the flexible legs 22, 24, and 26 of the deformable portion 20. A linear actuation coil 42 is obtained by winding copper wire around the rear portion 23. The magnet 41 is a neodymium permanent magnet, which is bonded to the front portion 21 using an acrylic adhesive.

[0079] exist Figure 4In the second embodiment shown, elements similar to those in the first embodiment have the same reference numerals. The microrobot 10 of the second embodiment differs from that of the first embodiment in that the guide segments 3, 5, and 7 comprise photoactive materials instead of electroactive materials. For each guide segment 3, 5, and 7 based on photoactive materials, the propulsion and manipulation device 1 includes a dedicated radiation source whose radiation is directed to the opposite side of the guide segment to activate its deformation. As an example, in this second embodiment, the photoactive material of each guide segment 3, 5, and 7 is a liquid crystal network comprising azobenzene molecules, and the radiation source of each guide segment 3, 5, and 7 is a white light source, with different sources housed within the same housing 8'.

[0080] In this second embodiment, all guide segments 3, 5, and 7 are based on the same photoactive material, and to avoid radiation interactions that might activate guide segment deformations other than those associated with a dedicated radiation source, respective optical fibers 83', 85', and 87' are used to transmit radiation upwards to the photoactive material of each guide segment 3, 5, and 7, the optical fibers having distal ends positioned relative to the photoactive material of the guide segments 3, 5, and 7. According to a variation, guide segments 3, 5, and 7 may be based on different photoactive materials adapted to be activated by radiation of different wavelengths. In this case, each guide segment 3, 5, and 7 is associated with a radiation source emitting within its specific wavelength range. Again, this embodiment can use optical fibers having distal ends positioned relative to the photoactive material of the guide segments to transmit radiation upwards to the photoactive material of the guide segments 3, 5, and 7.

[0081] exist Figure 5 In the third embodiment shown, elements similar to those in the first embodiment have the same reference numerals. The difference between the microrobot 10 of the third embodiment and the first embodiment is that the deformable portion 20 of the propulsion element 2 is a helical spring comprising two flexible legs 22, 24 (instead of three flexible legs as in the first embodiment). The two flexible legs 22, 24 are helically arranged between the front portion 21 and the rear portion 23 of the propulsion element around the main axis X2, and each has three guide segments based on an electroactive material, namely 31, 32, 33 and 51, 52, 53. For each of the two flexible legs 22, 24, the guide segments 31, 32, 33 or 51, 52, 53 are distributed along the flexible leg and connected to the power supply 8 via corresponding wires. All wires of the different guide segments of the flexible legs 22 or 24 pass through cables 83 or 85.

[0082] exist Figure 6In the fourth embodiment shown, elements similar to those in the first embodiment have the same reference numerals. The microrobot 10 of the fourth embodiment differs from that of the first embodiment in that the deformable portion 20 of the propulsion element 2 is a helical spring comprising a single flexible leg 22, which is helically arranged between the front portion 21 and the rear portion 23 of the propulsion element about the main axis X2. The flexible leg 22 comprises four guide segments 31, 32, 33, and 34 based on an electroactive material. These guide segments are distributed along the flexible leg 22 and each is connected to a power source 8 via a corresponding wire. All wires of the different guide segments of the flexible leg 22 pass through a cable 83. The guide segments 31, 32, 33, and 34 are configured to cause the propulsion element 2 to rotate about a first rotation axis and a second rotation axis, respectively, which are transverse to each other and transverse to the main axis X2 of the propulsion element.

[0083] exist Figure 7 In the fifth embodiment shown, elements similar to those in the first embodiment have the same reference numerals. The microrobot 10 of the fifth embodiment differs from that of the first embodiment in that the propulsion and manipulation device 1 includes two propulsion elements 21 and 22 arranged sequentially. The control unit 9 is configured to actuate the stretching / contraction deformation cycles of the deformable portions 201 and 202 of the two propulsion elements according to a predetermined time sequence to induce non-reciprocating motion of the microrobot 10. This arrangement, unlike propulsion cilia, is used to achieve non-reciprocating motion of the microrobot 10, thereby allowing efficient movement in fluids with low Reynolds numbers.

[0084] In this fifth embodiment, for each of the two propulsion elements 21 and 22, the deformable portion 201 or 202 is the same as the deformable portion 20 in the first embodiment, i.e., it includes a portion surrounding the main axis X of the propulsion element. 21 or X 22 The three flexible legs 221, 241, 261 or 222, 242, 262 are spirally arranged. Each flexible leg 221, 241, 261 or 222, 242, 262 is provided with corresponding guide sections 31, 51, 71 or 32, 52, 72. These guide sections are based on electroactive materials and can reversibly deform under the action of power supply. They are connected to power supply 81 or 82 through corresponding cables 831, 851, 871 or 832, 852, 872.

[0085] The propulsion and maneuvering device 1 of this fifth embodiment does not include a linear actuator similar to the electromagnetic transducer 4 of the previous embodiment to sequentially actuate the elongation / contraction cycle of the deformable portions 201 or 202 of the propulsion elements. In fact, in this fifth embodiment, for each of the two propulsion elements 21 and 22, the guide segments 31, 51, 71 or 32, 52, 72 based on electroactive materials are configured such that when these guide segments deform simultaneously, they actuate the deformable portion 201 or 202 along the main axis X. 21 or X 22 The elongation / contraction deformation, and when these guide segments selectively deform, actuate the propulsion element 21 or 22 about transverse to the main axis X. 21 or X 22 The rotation of the axis of rotation. By selectively supplying electrical energy to the guide sections 31, 51, 71, 32, 52, 72, the rotation and / or elongation / contraction deformation of each propulsion element 21, 22 can be actuated, which allows the microrobot 10 to be oriented and propulsed.

[0086] exist Figures 8 to 10 In the sixth embodiment shown, elements similar to those in the first embodiment have the same reference numerals. The microrobot 10 of the sixth embodiment differs from that of the first embodiment in that the guiding element comprises two electromagnetic guiding coils 43 and 45, instead of a guiding segment based on an active material. Each of the guiding coils 43 and 45 is provided with a corresponding connection 63, 65 to an electrical energy source 6, and forms an electromagnetic transducer with a permanent magnet 41 fixed to the front portion 21 of the propulsion element 2. The magnet 41 is substantially parallel to the main axis X2 of the propulsion element in its resting position. Each of the two guiding coils 43, 45 is adapted to cause rotation of the magnet 41 relative to its resting position under the influence of electrical energy, resulting in rotation of the propulsion element 2 about an axis of rotation transverse to the main axis X2.

[0087] The propulsion and manipulation device 1 of the sixth embodiment also includes a linear actuation electromagnetic coil 42 similar to the coil 42 of the previous embodiment. This electromagnetic coil is provided with a corresponding connection 62 to the electrical energy source 6 and also forms an electromagnetic transducer with the magnet 41. The linear actuation coil 42 is adapted to cause the magnet 41 to translate parallel to the main axis X2 under the action of the electrical energy supply, which results in the stretching / contraction deformation of the deformable portion 20 along the main axis X2. By selectively powering the guide coils 43, 45 and the linear actuation coil 42, the rotation and stretching / contraction deformation of the propulsion element 2 can then be actuated, which allows for ensuring the directional manipulation and propulsion of the microrobot 10.

[0088] The linear actuation coil 42 and the guide coils 43 and 45 are arranged in the relevant manner. Figure 10The enlarged view shows the corresponding recesses 232, 233, and 235 for accommodating coils 42, 43, and 45. The central axis of the linear actuation coil 42, accommodated in recess 232, is aligned with the main axis X2 of the propulsion element 2. The central axis of the guide coil 43, accommodated in recess 233, extends upward relative to the main axis X2 of the propulsion element 2 and extends to... Figure 10 The orientation offset in the view plane. Finally, the central axis of the guide coil 45 housed in the groove 235 is relative to the main axis X2 of the propulsion element 2 in a downward direction and from... Figure 10 The direction of the view plane being emitted is offset.

[0089] exist Figure 11 In the seventh embodiment shown, elements similar to those in the sixth embodiment have the same reference numerals. In this seventh embodiment, the propulsion and manipulation device 1 includes three guide coils 43, 45, and 47 (not shown), each with a corresponding connection to an electrical energy source and configured to form an electromagnetic transducer with a permanent magnet 41 fixed to the front portion of the propulsion element 2. Figure 11 The image shows corresponding recesses 233, 235, and 237 for accommodating guide coils 43, 45, and 47. The three guide coils 43, 45, and 47 are arranged sequentially along the main axis X2 of the propulsion element 2, and the central axes of these guide coils are substantially parallel to and do not coincide with the main axis X2.

[0090] Especially in Figure 11 In the example shown, the central axis of the guide coil 43 housed in the groove 233 extends downward relative to the main axis X2 of the propulsion element 2 and extends to... Figure 11 The orientation offset in the view plane. The central axis of the guide coil 45, housed in the groove 235, extends upward relative to the main axis X2 of the propulsion element 2 and extends to... Figure 11 The orientation offset in the view plane. Finally, the central axis of the guide coil 47 housed in the groove 237 is relative to the main axis X2 of the propulsion element 2 in a downward direction and from... Figure 11 The direction of the projected image plane is offset. The three guide coils 43, 45, and 47 are configured such that when these guide coils are simultaneously powered, they actuate the deformable portion 20 of the propulsion element 2 to elongate / contract along the main axis X2, and when these guide coils are selectively energized, they cause the magnet 41 to rotate relative to its resting position, thereby causing the propulsion element 2 to rotate about a rotation axis transverse to the main axis X2.

[0091] exist Figure 12In the eighth embodiment shown, elements similar to those in the sixth embodiment have the same reference numerals. In this eighth embodiment, the propulsion and manipulation device 1 includes a linear actuation coil 42 and three guide coils 43, 45, 47 (not shown), each having a corresponding connection to an electrical energy source and configured to form an electromagnetic transducer with a permanent magnet 41 fixed to the front portion of the propulsion element 2. Figure 12 The diagram shows corresponding recesses 232, 233, 235, and 237 for accommodating coils 42, 43, 45, and 47. A linear actuation coil 42 is disposed at the rear of the propulsion element 2, its central axis being substantially parallel to the main axis X2 of the propulsion element 2. Three guide coils 43, 45, and 47 are distributed around the linear actuation coil 42 and are equidistant from each other, their central axes being substantially perpendicular to the main axis X2.

[0092] In this eighth embodiment, the actuation of the elongation / contraction deformation of the deformable portion 20 along the main axis X2 is obtained by supplying power to the linear actuation coil 42, while the actuation of the rotation of the magnet 41 relative to its rest position, thereby causing the propulsion element 2 to rotate about a rotation axis transverse to the main axis X2, is obtained by selectively supplying power to the guide coils 43, 45, 47.

[0093] exist Figure 13 and Figure 14 In the ninth and tenth embodiments shown respectively, elements similar to those in the sixth embodiment have the same reference numerals. In these ninth and tenth embodiments,

[0094] According to the ninth and tenth embodiments, the propulsion element 2 is shown. Figure 3 The propulsion element in the illustrated embodiment includes a front portion 21, a rear portion 23, and a deformable portion 20 connecting the front portion 21 and the rear portion 23. In this ninth and tenth embodiments, the deformable portion 20 is a helical spring that can stretch / contract along the main axis X2 of the propulsion element 2. The axis X2 is defined in the same manner as before, such as the central axis of the deformable portion 20, which is substantially perpendicular to the plane of the distal end plate 230 to which the deformable portion 20 is fastened. The helical spring forming the deformable portion 20 includes three flexible legs 22, 24, and 26, which are helically arranged between the front portion 21 and the rear portion 23 of the propulsion element 2 about the main axis X2.

[0095] In the ninth and tenth embodiments, the helical spring forming the deformable portion 20 cooperates with at least one guide element 3, 5, 7, each extending between the front portion 21 and the rear portion 23 of the propulsion element 2. In embodiments not shown, the guide element extends around the helical spring. In the ninth and tenth embodiments, the helical spring extends around at least one guide element 3, 4, 5. More specifically, in the ninth and tenth embodiments, the device 1 includes three guide elements 3, 5, 7, each forming a deformable leg or segment, which is helically disposed between the front portion 21 and the rear portion 23 of the propulsion element about the main axis X2. Figure 13 In the ninth embodiment shown, deformable segments 3, 5, 7 and flexible legs 22, 24, 26 are evenly distributed on the circumference of the propulsion element 2, so that the propulsion element 2 has alternating circumferences of flexible legs 22, 24, 26 and deformable segments 3, 5, 7. Figure 14 In the tenth embodiment shown, each deformable segment 3, 5, 7 is radially aligned with the flexible legs 22, 24, 26 of the helical spring. Therefore, in Figure 13 , Figure 14 In each of the embodiments, each flexible leg 22, 24, 26 cooperates with guide elements 3, 5, 7.

[0096] Similar to the foregoing embodiments, each deformable segment 3, 5, 7 comprises, for example, an electroactive material (e.g., a PEDOT ionic electroactive polymer). Therefore, each of the three guiding elements 3, 5, 7 can reversibly deform under the influence of electrical power. Each guiding element 3, 5, 7 is adapted to cause deformation of the corresponding flexible legs 22, 24, 26 and rotation of the propulsion element 2 by its deformation when powered by electrical energy. For each guiding segment 3, 5, 7, the axis of rotation caused by the deformation of the guiding segment is transverse to the main axis X2 of the propulsion element 2 and transverse to the axis of rotation caused by the deformation of each of the other two guiding elements. The isotropic distribution of the guiding segments 3, 5, 7 around the main axis X2 of the propulsion element 2 allows for optimized directional manipulation of the propulsion element 2, as in the first embodiment. Therefore, regardless of the embodiment, it should be noted that in this invention, the guiding segments 3, 5, 7 and the flexible legs 22, 24, 26 form a unique multi-purpose functional group ensuring rotation and propulsion. This invention is not characterized by any coupling of different elements each ensuring different functions.

[0097] exist Figure 15 and Figure 16In the eleventh embodiment shown, elements similar to those in the first embodiment have the same reference numerals. In the eleventh embodiment, the device 1 for propulsing and manipulating the microrobot 10 is configured, as in the previous embodiments, to move in a viscous or viscoelastic material (e.g., in the cerebrospinal fluid or extracellular matrix of the subject's brain), which is a fluid material with a low Reynolds number.

[0098] exist Figure 15 and Figure 16 The image shows an alternative embodiment of the propulsion element 2. In this eleventh embodiment, the propulsion element 2 includes a front portion 21, a rear portion 23, and a deformable portion 20 connecting the front portion 21 and the rear portion 23. The deformable portion 20 is divided into a front sub-portion 20A and a rear sub-portion 20B, which are connected together by an oscillating disk 30. The oscillating disk 30 is located between the front portion 21 and the rear portion 23, equidistant from each of them. Figure 15 and Figure 16 In the example shown, the oscillating disk 30 has a diameter similar to that of the distal plate 230. However, in embodiments not shown, the diameter of the oscillating disk 30 may be larger than that of the distal plate 230.

[0099] When at rest, the oscillating disk 30 is substantially parallel to the distal end plate 230. In this embodiment, the oscillating disk 30 of the propulsion element 2 includes a plurality of propulsion cilia 28 on its surface, which are configured to interact with a material in which the microrobot 10 moves. The sequential elongation / contraction cycle of the deformable portion 20 causes the propulsion cilia 28 to move in the material, thereby generating a propulsive force that causes the microrobot 10 to move. Therefore, it can be advantageous for the oscillating disk 30 to have a larger diameter than the distal end plate 230 to facilitate the attachment of the propulsion cilia 28 to the oscillating disk.

[0100] In this eleventh embodiment, the front sub-section 20A of the deformable portion 20 is a helical spring that can extend / contract along the main axis X2 of the propulsion element 2. The main axis X2 of the propulsion element 2 is defined herein in a manner similar to that of the previous embodiments, and like the central axis of the deformable portion 20, this central axis is substantially perpendicular to the plane of the distal end plate 230 to which the deformable portion 20 is fastened. The helical spring forming the front sub-section 20A of the deformable portion 20 includes three flexible legs 22, 24, and 26, which are helically arranged between the front portion 21 of the propulsion element and the oscillating disk 30 around the main axis X2.

[0101] In this eleventh embodiment, the rear sub-part 20B of the deformable portion 2 includes at least one guiding element 3, 5, 7 based on an electroactive material (e.g., PEDOT ionic electroactive polymer). More specifically, in the eleventh embodiment of the invention, the deformable portion 2 includes three guiding elements 3, 5, 7 forming guiding segments 3, 5, 7. Each of the three guiding segments 3, 5, 7 is reversibly deformable by an electrical power supply and is connected to a power source. At rest, the three guiding segments 3, 5, 7 have the same length. Figure 15 Clearly shown, guide segments 3, 5, and 7 are isotropically distributed around the main axis X2 of the propulsion element 2, which allows for optimized directional control of the propulsion element. Each of the three guide segments 3, 5, and 7 forms a leg extending between the rear portion 23 of the deformable part 2 and the oscillating disk 30. More specifically, the three guide segments are helically arranged around the main axis X2 between the rear portion 23 of the propulsion element 2 and the oscillating disk 30. As already mentioned, each guide segment 3, 5, and 7 is adapted to cause tilting of the oscillating disk 30 by its deformation when powered by electrical energy. This... Figure 16 As shown in the diagram, with each of the three guide segments 3, 5, and 7 activated, the oscillating disk 30 tilts in different directions, causing a rotational oscillating motion. This rotational oscillating motion causes the propulsion element 2 to rotate. For each guide segment 3, 5, and 7, the axis of rotation caused by the deformation of the guide segment is transverse to the main axis X2 of the propulsion element and transverse to the axis of rotation caused by the deformation of each of the other two guide segments. Therefore, also in this embodiment, despite the presence of the oscillating disk 30, the guide segments 3, 5, and 7 directly engage with the flexible legs 22, 24, and 26, forming a unique multi-purpose functional group with these flexible legs that ensures both rotation and propulsion. The invention is not characterized by any coupling of different elements that each ensures different functions.

[0102] As demonstrated in the preceding examples, the propulsion and manipulation device according to the invention allows for reliable and accurate movement of a microstructure in 3D space by actuating, on the one hand, the propulsion element to rotate about at least two rotational axes transverse to each other and transverse to the main axis, and on the other hand, by actuating the deformation of the deformable portion of the propulsion element to induce propulsion of the microstructure. Advantageously, since an energy supply can be independently initiated for each guiding element and, if present, for a linear actuator, all spatial and temporal combinations for actuating the rotation and deformation of the deformable portion of the propulsion element can be considered. In particular, rotation and deformation can be actuated simultaneously or sequentially, as needed, allowing the microstructure to move according to a desired trajectory in its environment.

[0103] It should be remembered that at the millimeter scale, in low Reynolds number environments, moving even the smallest component requires a significant amount of energy. The frictional forces involved are considerable. Although it depends on the type of friction (dry friction, viscous friction, etc.) and the robot's size, it is generally known that low Reynolds numbers mean that surface forces dominate compared to volume forces. In such cases, for example, optimizing the robot's overall size is more appropriate than optimizing its weight.

[0104] Therefore, the smaller the device, the fewer functional components it contains, and the lower the energy consumption for moving the device. Due to the smaller size of the device and the reduction in the number of functional components (made possible by the multifunctional aspects of different components, especially the guide segment), the present invention achieves significant energy savings for a given movement.

[0105] The present invention is not limited to the examples described and shown.

[0106] Specifically, in the previous example, the deformable portion of the propulsion element was a helical spring with one, two, or three flexible legs. Alternatively, the deformable portion of the propulsion element could comprise a helical or non-helical spring with any number of flexible legs, or a deformable structure other than a spring (e.g., a bellows). The deformable portion of the propulsion element could also comprise a combination of a spring and a bellows, each fold of the bellows positioned, for example, at one turn of the spring, and the envelope of the bellows filling the space between consecutive turns of the spring.

[0107] Furthermore, in cases where the propulsion and manipulation equipment includes a dedicated linear actuator for actuating the elongation / contraction deformation of the deformable portion of the propulsion element, the linear actuator can be different from the actuator involving electromagnetic transducers and permanent magnets as described above. In particular, in cases where the deformable portion has a sealed envelope, such as in the case of a bellows, the actuator for actuating the elongation / contraction deformation of the deformable portion can be a pump, and the elongation / contraction of the deformable portion can then be achieved by the alternating flow of fluid into / out of the internal space of the deformable portion actuated by the pump.

[0108] Furthermore, in previous examples implementing guide segments including active materials, the active materials in different guide segments all possessed the same properties. Alternatively, the propulsion and manipulation device according to the invention may include multiple guide segments containing active materials with different compositions or properties. For example, a guide segment including an electroactive material may be combined with a guide segment including a bimetallic element; or a guide segment including a photoactive material may be combined with a guide segment including an electroactive material or a bimetallic element, with different energy supply connectors for activating the guide segments adjusted accordingly. Guide segments based on active materials may also be combined with… Figures 8 to 12 The embodiments of those types of guide coil combinations.

[0109] In cases where the propulsion and manipulation equipment includes a guide coil as a guide element for inducing rotation of the propulsion element, it is also possible to consider... Figures 8 to 12 Different guide coil arrangements are described in the embodiments. In particular, the number of guide coils is any number greater than or equal to two, and the guide coils can be arranged sequentially, one after another, or even concentrically, and may be combined with or not combined with linear actuation coils.

[0110] Advantageous arrangements, not shown in the figure, include, for example: three guide coils distributed around the main axis of the propulsion element, their central axes substantially parallel to the main axis, and equidistant from each other; or six guide coils distributed around the main axis of the propulsion element, their central axes substantially parallel to the main axis, and equidistant from each other. In both cases, the guide coils can be positioned at the rear of the propulsion element without linear actuation coils, where actuation of the elongation / contraction deformation of the deformable portion along the main axis is achieved by simultaneously powering all guide coils with electrical energy, while actuation of the propulsion element about a rotation axis transverse to the main axis due to rotation of the magnet relative to its resting position is achieved by selectively powering the guide coils; or they can be positioned at the rear of the propulsion element in combination with linear actuation coils, where actuation of the elongation / contraction deformation of the deformable portion along the main axis is achieved by powering the linear actuation coils, while actuation of the propulsion element about a rotation axis transverse to the main axis due to rotation of the magnet relative to its resting position is achieved by selectively powering the guide coils.

[0111] Finally, the present invention has been demonstrated for the propulsion and manipulation of microrobots designed to move in viscous or viscoelastic materials, such as cerebrospinal fluid or extracellular matrix of a subject's brain. Alternatively, the propulsion and manipulation device according to the invention can of course be implemented to move other types of microstructures in the medical or other fields, and in particular, the device according to the invention can be used to propel and manipulate movable flexible tubes (e.g., stents or catheters).

Claims

1. A device for using 10 -5 Up to 10 -1 A device for propelling and manipulating microstructures in a low Reynolds number fluid (1), the device having an outer diameter of less than or equal to 5 mm, and the device being designed to move within a blood vessel or organ of a subject, the device comprising: - A propulsion element (2) comprising at least one deformable portion (20) that is capable of elongating / contracting along the main axis (X2) and connecting the front portion (21) and the rear portion (23) of the propulsion element (2); - At least two guiding elements adapted to cause the propulsion element (2) to rotate about a first rotation axis and a second rotation axis respectively under the action of energy supply through a corresponding connection with an energy source, the first rotation axis and the second rotation axis being transverse to each other and transverse to the main axis (X2) of the propulsion element, at least one guiding segment comprising an electroactive material or a bimetallic element; - Electrical energy source, which is connected to the guide segment to activate its deformation; - A control unit (9) configured to actuate the rotation of the propulsion element (2) about at least one axis transverse to the main axis (X2) by selectively controlling one or more of the connectors to the energy source in a manner that engages with the elongation / contraction deformation of the deformable portion (20) of the propulsion element (2) along the main axis (X2). The guiding element also includes at least two guiding segments based on an active material, said at least two guiding segments being reversibly deformable under the action of energy supply through the corresponding connectors to the energy source. Each guiding segment is adapted to cause the propulsion element (2) to rotate about a rotation axis transverse to the main axis (X2) of the propulsion element by its deformation under the action of energy supply.

2. The device according to claim 1, wherein at least one guide segment comprises a photoactive material, and the device (1) comprises a radiation source whose radiation is emitted opposite to the guide segment to activate its deformation.

3. The device according to claim 1 or 2, wherein at least two of the guide segments are configured such that when the at least two guide segments deform simultaneously, the deformable portion (20) of the actuating propulsion element (2) elongates / contracts along the main axis (X2), and when the at least two guide segments deform selectively, the actuating propulsion element (2) rotates about a rotation axis transverse to the main axis (X2).

4. The device according to claim 1 or 2, wherein the guiding element comprises at least two electromagnetic guiding coils (43, 45), each of the at least two electromagnetic guiding coils having a corresponding connection to an electrical energy source and forming an electromagnetic transducer (4) with a magnet (41) fixed to the propulsion element (2), the magnet (41) being parallel to the main axis (X2) of the propulsion element (2) in a resting position, each electromagnetic guiding coil (43, 45) being adapted to cause the magnet (41) to rotate relative to its resting position under the action of an electrical energy supply, thereby causing the propulsion element (2) to rotate about a rotation axis transverse to the main axis (X2) of the propulsion element.

5. The device according to claim 4 further includes a linear actuating electromagnetic coil (42), which is provided with a corresponding connection to an electrical energy source and also forms an electromagnetic transducer (4) with a magnet (41) fixed to the propulsion element (2), the linear actuating electromagnetic coil (42) being adapted to cause the magnet to translate parallel to the main axis (X2) under the action of an electrical energy supply, thereby causing the deformable portion (20) of the propulsion element (2) to elongate / contract along the main axis (X2).

6. The device according to claim 1 or 2, wherein the control unit (9) is further configured to actuate the elongation / contraction deformation of the deformable portion (20) of the propulsion element (2) along the main axis (X2).

7. The device according to claim 1 or 2, comprising an actuator configured to actuate the elongation / contraction deformation of the deformable portion (20) of the propulsion element (2) along the main axis (X2).

8. The device according to claim 1 or 2, characterized in that, The at least two guide elements are radially positioned outside the deformable portion (20).

9. The device according to claim 1, wherein the microstructure is a flexible tube or a microrobot.

10. The device according to claim 7, wherein the actuator is an electromagnetic transducer or a pump.

11. The device according to claim 1 or 2, characterized in that, The deformable portion (20) includes an oscillating disk (30) disposed between the front portion (21) and the rear portion (23), and the at least two guiding elements are disposed between the rear portion (23) and the oscillating disk (30).

Images