Resonant system-LIMP

Abstract

A microrobot (100) includes a body (101) configured to vibrate, and an actuator (12) configured to generate vibrations that move the microrobot. The invention relates to a microrobot comprising a steering system (10) comprising a resonant structure (16) configured to be fixed to the microrobot and comprising:-a steering structure (18) for controlling the propulsion direction,-a weight resonator (20) configured to be activated by an appropriate activation resonance frequency. The actuator is configured to generate vibrations within a frequency range including an appropriate activation resonance frequency of each weight resonator. The resonant structure has at least two states:-an active steering state in which at least one of the weight resonators is activated at a suitable activation resonance frequency to change the propulsion direction,-an inactive steering state in which no weight resonators are activated at its suitable activation resonance frequency to change the propulsion direction,-an inactive steering state in which no weight resonators are activated at its suitable activation resonance frequency to change the propulsion direction. Therefore, the propelling direction is kept.

Description

Technical Field

[0001] The present invention relates to a steering system for a microrobot intended to circulate in a viscous environment, in particular in the human body. Background Art

[0002] Being able to reach deep functional structures without damage is a major challenge in minimally invasive surgery, especially neurosurgery. Thanks to microtechnology, it is possible to send fully autonomous microrobots into the subject's organs (such as the brain). However, propelling microrobots in low Reynolds number environments (such as in the brain) is a challenge because the microrobots are small, lack inertia, and have relatively large resistance. Another important requirement is that the microrobot should be able to move within the organ while limiting the physiological damage caused to the organ as much as possible during its passage.

[0003] In this context, the present invention aims to propose a microrobot that has an efficient propulsion mechanism in a viscous environment with low Reynolds number while maintaining the integrity of its environment as much as possible. Summary of the Invention

[0004] Therefore, the present invention relates to a microrobot configured to move in a propulsion direction by vibration, the microrobot comprising a body configured to vibrate, and an actuator configured to generate vibrations that cause the microrobot to move, the microrobot further comprising a steering system, the steering system comprising a resonant structure configured to be fixed to the microrobot, the resonant structure comprising:

[0005] - steering structures, which are intended to control the direction of propulsion,

[0006] - distributed weight resonators, each weight resonator being configured to be activated by a suitable activation resonance frequency, the respective suitable activation resonance frequencies of the weight resonators being different from one another,

[0007] wherein the actuator is configured to generate vibrations within a frequency range that includes an appropriate activation resonant frequency of each weight resonator,

[0008] Among them, the resonant structure has at least two states:

[0009] - at least one activation steering state, in which at least one of the weight resonators is activated at an appropriate activation resonance frequency to change the direction of propulsion of the microrobot,

[0010] - an inactive steering state, in which no weight resonator is activated at its proper activation resonance frequency, thereby maintaining the microrobot's propulsion direction.

[0011] Therefore, the present solution achieves the above-mentioned objectives. Specifically, it is able to realize the rotation of the microrobot based solely on the motion (energy) generated by the microrobot itself (more precisely, the micromotor of the microrobot), thereby avoiding the addition of additional energy, which may require the addition of other components or devices in the patient's body, or the transmission of additional energy to the microrobot, all of which may increase the risk of damaging the environment in which the microrobot moves.

[0012] The device according to the invention may comprise one or more of the following features, which may be considered individually or in combination:

[0013] - the resonant structure may have several activated steering states, each activated steering state being associated with a different suitable activated resonant frequency,

[0014] o at least one activated steering state is a state in which the configuration and movement of the resonant structure are intended to change the propulsion direction of the microrobot,

[0015] The inactive steering state is the state in which the configuration and motion of the resonant structure are intended to maintain the propulsion direction of the microrobot.

[0016] The resonant structure may further comprise distributed multistable elements, each multistable element being deformable between at least two stable configurations:

[0017] - at least a first stable configuration when the resonant structure is in its activated steering state,

[0018] - at least a second stable configuration when the resonant structure is in its inactive steering state,

[0019] the multistable element may be a bistable pre-compressed beam having a first stable configuration and a second stable configuration, the pre-compressed beam being bent in a first direction towards the body of the microrobot in the first stable configuration and being bent in a second direction away from the body of the microrobot in the second stable configuration,

[0020] - The steering structure may be a retractable steering vane having an extended and retracted configuration relative to the main body of the microrobot, the configuration of the steering vane being determined by the steering state of the resonant structure:

[0021] - the inactive steering state of the resonant structure triggers the retracted configuration of the retractable steering vanes, and

[0022] - the activated steering state of the resonant structure triggers the deployed configuration of the retractable steering flaps,

[0023] - each multistable element may be a multistable shell comprising a stack of several sheets,

[0024] - the steering system may further comprise at least one mobile cilium configured to be moved by vibration of the microrobot body,

[0025] - the resonant structure may comprise at least one strand of a propulsion spring contained within the body,

[0026] - activating the resonant structure to at least one of its activated steering states may induce retraction of at least one strand of the propulsion spring,

[0027] - the body of the microrobot may exhibit an overall circular symmetry about a propulsion axis parallel to the propulsion direction, wherein the resonant structure is another part of the body, and wherein activation of the resonant structure to one of its activated steering states induces a disruption of the overall circular symmetry of the body,

[0028] - at least one hair-like object may be part of a resonant structure, said at least one hair-like object exhibiting a first motion intensity in an inactive steering state and a second motion intensity in an active steering state, the second motion intensity being different from the first motion intensity,

[0029] - Each ciliary organ may comprise a weight resonator. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be better understood and its other objects, details, features and advantages will become more apparent by reading the following detailed description of embodiments of the present invention by way of purely illustrative and non-limiting examples in conjunction with the accompanying drawings.

[0031] - Figure 1a is a schematic side view of a microrobot including a steering system according to a first embodiment of the present invention,

[0032] - Figure 1b is a schematic side view of a microrobot including a steering system according to a second embodiment of the present invention,

[0033] - Figure 2a is a detailed schematic side view of a steering system according to a first embodiment of the present invention,

[0034] - Figure 2b is a detailed schematic side view of a steering system according to a second embodiment of the present invention,

[0035] - Figure 3a is a detailed schematic top view of a steering system according to a first embodiment of the present invention,

[0036] - Figure 3b is a detailed schematic top view of a steering system according to a second embodiment of the present invention,

[0037] - Figure 4 is a step-by-step schematic diagram of activation of the steering system according to the first embodiment,

[0038] - Figure 5a is a schematic side view of a microrobot including a steering system according to a third embodiment of the present invention,

[0039] - Figure 5b is a detailed schematic side view of a steering system according to a third embodiment of the present invention,

[0040] - Figure 5c is a detailed schematic top view of a steering system according to a third embodiment of the present invention,

[0041] - Figure 6 is a step-by-step schematic diagram of activation of a steering system according to a third embodiment of the present invention,

[0042] - Figure 7a is a schematic side view of a microrobot including a steering system according to a fourth embodiment of the present invention,

[0043] - Figure 7b is a detailed schematic side view of a steering system according to a fourth embodiment of the present invention,

[0044] - Figure 7c is a detailed schematic top view of a steering system according to a fourth embodiment of the present invention,

[0045] - Figure 8 is a step-by-step schematic diagram of activation of a steering system according to a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0046] Please note that in this application, the term "weight resonator" is defined broadly: it is not a resonator based solely on its weight. Weight resonators may also include fins and bi-stable or multi-stable elements that utilize the shape and internal tension of a component to create multiple stable states. These elements can be switched from one stable state to another by introducing energy. As explained in further detail below, this is achieved by shifting the resonant frequency to maximize the available / conducted energy.

[0047] Example

[0048] like Figure 1a and Figure 1b As shown, the steering system 10 according to the invention is intended as part of a microrobot 100 configured to move in a fluid environment, more precisely in a propulsion direction along a propulsion axis X. This movement in the propulsion direction occurs by vibrations in the fluid environment.

[0049] Thus, the microrobot 100 comprises a body 101 comprising an actuator 12 configured to generate vibrations. More precisely, in the embodiment shown, the actuator 12 is a vibration motor 12 comprising a coil 120 and a magnet 121. The coil 120 extends along a propulsion direction X and surrounds the magnet 121. The magnet 121 can be driven by the coil 120 and is configured to move back and forth along the propulsion direction X. The movement of the magnet 121 triggers a compression / decompression movement of a propulsion spring 14, which is also part of the vibration motor 12 and also extends along the propulsion direction X. The propulsion spring 14 allows a series of external flagella (pilis) or cilia (cilia) 15 to move, thereby enabling the microrobot 100 to move in a fluid environment.

[0050] Many fluid environments can be targeted, but all body fluids are of particular interest. For example, these body fluids include blood, cerebrospinal fluid, urine, bile, lymph, and aqueous humor. The viscosity of these fluids is close to that of water.

[0051] from Figure 1a and Figure 1b As can further be seen in FIG, the steering system 10 according to the invention comprises an elongated resonant structure 16 , which is intended to be fixed to the microrobot 100 .

[0052] The elongated resonant structure 16 comprises:

[0053] - a steering structure 18 intended to control the direction of propulsion,

[0054] - The distribution of weight resonators 20, which are configured to activate the resonance frequency f at a suitable (or given) activation frequency f A 、f A1 、f A2 is activated at the appropriate (or given) deactivation frequency f B is deactivated.

[0055] The corresponding appropriate activation resonance frequency f of each weight resonator 20 A 、f A1 、f A2 The appropriate activation resonance frequency f of the other weight resonators 20 A 、f A1 、f A2 The actuator 12 is configured to include an appropriate activation resonance frequency f of each weight resonator 20. A 、f A1 、f A2 The elongated resonant structure 16 has at least two states:

[0056] at least one active steering state A, A1, A2, wherein the configuration and movement of the elongated resonant structure 16 is configured to change the direction of propulsion of the microrobot 100,

[0057] An inactive steering state B, in which the configuration and movement of the elongated resonant structure 16 are configured to maintain the propulsion direction of the microrobot 100 .

[0058] Regardless of the embodiment, the state B, A, A1, A2 of the elongated resonant structure 16 is determined by the activation or deactivation of the weight resonator 20, as will be further explained below.

[0059] As will be further explained below, when the microrobot 100 moves along its propulsion direction, the activation and deactivation frequencies f of the weight resonator 20 B 、f A 、f A1 、f A2 It is caused by the vibration of the microrobot body 101 (more specifically, the vibration caused by the micromotor included in the microrobot body 101).

[0060] More specifically, regarding Figure 1a and Figure 1b , the elongated resonant structure 16 further comprises a distribution of multi-stable elements 22 fixed to the microrobot 100. Each multi-stable element 22 has at least two stable configurations and can be deformed between the at least two stable configurations:

[0061] - at least a first stable configuration C when the resonant structure 16 is in its activated steering state A, A1, A2 A 、C A1 、C A2 (See Figure 2a 、 Figure 2b ),

[0062] - at least a second stable configuration C when the resonant structure 16 is in its inactive steering state B B (See Figure 2a 、 Figure 2b ).

[0063] Depending on the embodiment, the multistable element 22, the weight resonator 20 and the steering structure 18 can be the same technical element or different elements. Figure 1a In the embodiment shown, the multistable element 22, the weight resonator 20 and the steering structure 18 are all different technical components. Figure 1b In the embodiment depicted, the multistable element 22, the weight resonator 20 and the steering structure 18 are identical technical elements. In this case, different suitable activation frequencies f A 、f A1 、fA2 It can be specialized, for example, to control the shape of the weight resonator 20 (or multistable element 22). For example, there can be one frequency for semi-enclosure and another for full enclosure.

[0064] More precisely, about Figure 1a 、 Figure 2a and Figure 3a In the depicted embodiment, the elongated resonant structure 16 comprises three multistable elements 22 equidistantly distributed around the body 101 of the microrobot 100 (see FIG. Figure 3a Each multi-stable element 22 is associated with a specific appropriate activation frequency f A The specific appropriate activation frequency f is associated with the weight resonator 20. A Different from the appropriate activation frequency f of other weight resonators 20 associated with other multistable elements 22 A In this example, each multistable element 22 is a bistable pre-compressed beam 22 having a length of 100 μm to several millimeters and made of polymer, glass or metal (e.g., stainless steel or alloy). In this particular embodiment, each beam 22 connects the steering structure 18 and the weight resonator 20. Each beam 22 has two ends, and each end is fixed to the microrobot 100. More precisely, each beam 22 is fixed in a small open cavity of the body 101 of the microrobot 100. As previously described, each beam 22 has a first stable configuration C A and the second stable configuration C B , in the first stable configuration C A In the second stable configuration C, the beam 22 bends into the cavity of the microrobot 100. B In the embodiment, the beam 22 bends outward from the cavity of the microrobot 100. The first stable configuration C A Corresponding to the activated steering state A, the second stable configuration C B corresponds to the inactive steering state B. In its inactive steering state B, the pre-compression beam 22 bends in a first direction, away from the main body 101 of the microrobot 100. In the active steering state A, the pre-compression beam 22 bends in a second direction, toward the main body 101 of the microrobot 100, and is therefore different from the first direction.

[0065] Still refer to Figure 1a and 2a In the embodiment, the steering structure 18 includes a retractable steering wing 18 having an open and retracted configuration relative to the main body 101 of the micro robot 100 (see Figure 2a). As will be described later, the configuration of the steering vanes 18 depends on the state of the elongated resonant structure 16 of the steering system 10. The vanes can be made of a variety of different flexible materials (for example, metals such as copper or alloys, glass, or polymers). The dimensions can vary from about 100 μm to several millimeters. More precisely, the inactive steering state B of the elongated resonant structure 16 causes the retracted configuration of the retractable steering vanes 18. On the other hand, the active steering state A of the elongated resonant structure 16 causes the deployed configuration of the retractable steering vanes 18.

[0066] Still refer to Figure 1a Each weight resonator 20 comprises a resonant mass connected to a beam 22. This mass can have any suitable shape, such as a bead or cube. Depending on the embodiment, the resonant mass can also be embedded in the beam 22 by adding additional thickness or extending the shape of the beam 22. Thus, activation of the resonant mass of a weight resonator 20 triggers a configuration change in the beam 22. This configuration change in the beam 22a further triggers a configuration change in the corresponding steering vane 18.

[0067] exist Figure 1b 、 Figure 2b and Figure 3b In the embodiment shown, the multistable element 22 is a multistable shell 22 comprising several stacked sheets. The multistable element can be made of a variety of flexible materials that have multistable capabilities after appropriate shaping, such as copper. The dimensions can vary from about 100 μm to several millimeters.

[0068] In this embodiment, the multistable housing 22 has an inactive steering state B, in which there is no resistance from the housing to the system's motion by blocking the flow of fluid, and several active steering states A1 and A2. Each active steering state A1, A2 is associated with a different, suitable activation resonant frequency f1 and f2. In these active states, the housing is positioned relative to the flow, creating asymmetry and inducing rotation in the direction in which the housing is exposed.

[0069] Specifically, according to Figure 5a and Figure 7a In another embodiment shown, the steering system 10, and more specifically, the elongated resonant structure 16, includes at least one mobile cilium 24. In some embodiments, the elongated resonant structure 16 includes at least one, and preferably a plurality of, mobile cilium 24. The at least one mobile cilium 24 can be part of a series of external flagella or cilia 15 that enable the microrobot 100 to move in a fluid environment (see the first paragraph under the subheading "Examples" in the detailed description). The at least one mobile cilium 24 can also be a separate technical element from the series of external flagella or cilia 15.

[0070] exist Figure 5a and Figure 7a In an embodiment, at least one hair-like structure 24 is part of the steering structure 18. In this embodiment, the steering structure is further configured to preferentially activate a single hair-like structure 24 over other hair-like structures 24. To achieve this, the steering structure may include a wing carried by the at least one hair-like structure 24. The wing-like structure may be oriented differently depending on the configuration and / or position of the at least one hair-like structure 24. These different configurations / positions enable the steering structure 18 to control the direction of propulsion of the microrobot 100.

[0071] Each of the ciliary hairs 24 is fixed to the main body 101 of the microrobot 100, preferably to the head of the microrobot 100. More precisely, each of the ciliary hairs 24 is fixed to the moving part 102 of the main body 101 of the microrobot 100. The moving part 102 is connected to the propulsion spring 14 of the vibration motor 12 and moves according to the propulsion spring 14. According to the movement of the propulsion spring 14, the moving part 102 can be centered or deviated with respect to the propulsion direction X. Therefore, each of the ciliary hairs 24 is configured to move by the vibration of the microrobot 100, more specifically, by the movement of the propulsion spring 14 of the motor (actuator) 12.

[0072] In this embodiment, the propulsion spring 14 comprises several strands 140, some of which are equipped with weight resonators 20 (see Figure 5b Thus, in this embodiment, the elongated resonant structure 16 comprises at least one strand 140 of the propulsion spring 14 of the vibration motor / actuator 12 .

[0073] More specifically, in Figure 5a 、 Figure 5b 、 Figure 5c and Figure 6 In the embodiment shown, each spring 140 that carries the weight resonator 20 is part of the multistable element 22 of the steering system 10. Similar to the previous embodiment, each weight resonator 20 can be activated at an appropriate resonant frequency f A 、f A1 、f A2 It is activated at a given deactivation frequency fB and deactivated at a given deactivation frequency fB. Figure 5b As shown, the propulsion spring 14 comprises three independent strands 140, each of which carries a weight resonator 20, which can be activated at different appropriate activation frequencies f A 、f A1 、f A2 Activate it. Figure 5b As shown, different weight resonators 20 have different sizes and shapes, resulting in different appropriate activation frequencies f A、f A1 、f A2 In alternative embodiments, different suitable activation frequencies f A 、f A1 、f A2 It can be used specifically for example to control the shape of the weight resonator 20. It is possible to have one frequency for semi-enclosed and another for fully enclosed.

[0074] In this embodiment ( Figure 5a 、 Figure 5b 、 Figure 5c and Figure 6 ), activating the elongated resonant structure 16 to at least one of its activated steering states A, A1, A2 (see Figure 6 ), and more specifically, activation of each weight resonator 20 triggers the retraction of the corresponding strand 140 of the propulsion spring 14 .

[0075] More specifically, in this embodiment ( Figure 5a 、 Figure 5b 、 Figure 5c and Figure 6 ), each spring 140 presents the first stable configuration C A and the second stable configuration C B , in the first stable configuration C A In this state, the spring 140 has a first length L corresponding to the activated steering state A1, A2. A , in the second stable configuration C B In this state, the spring 140 has a second length L corresponding to the inactive steering state B. B When the spring 140 is in its second stable configuration C B When its length L B The same length as the other strands 140. In this second stable configuration, the moving part 102 of the main body 101 of the microrobot 100 is centered relative to the elongation axis X of the microrobot 100. The elongation axis X is the same as the propulsion axis X mentioned above. When the strand spring 140 is in its activated configuration C A When the elongated resonant structure 16 is in the activated state A1 or A2, its length changes and the moving part 102 of the main body 101 of the microrobot 100 deviates from the center. Therefore, activating the elongated resonant structure 16 to one of its activated turning states A1 or A2 causes a disruption of the overall symmetry of the main body 101 of the microrobot 100.

[0076] for Figure 1a 、 Figure 2a 、 Figure 3a and Figure 1b 、 Figure 2b and Figure 3bThe respectively depicted embodiments can also be said that activation of the elongated resonant structure 16 to its activated rotational states A1 , A2 induces a disruption of the overall symmetry of the body 101 of the microrobot 100 : the deployment of the flaps 18 a , 18 b disrupts the overall rotational symmetry of the microrobot 100 .

[0077] The length of each spring 140 depends on the activation / deactivation of each associated weight resonator 20. Therefore, the length of each spring 140 depends on the vibration amplitude of the vibration motor 12 and the propulsion spring 14, ranging from approximately 0 (no movement) to an amplitude of several hundred μm.

[0078] In the last depicted embodiment of the invention ( Figure 7a 、 Figure 7b 、 Figure 7c and Figure 8 ), at least one hair-like object 24 is also part of the elongated resonant structure 16. However, it is also part of the steering structure 18 and the multistable element 22. As in the previous embodiment, each hair-like object 24 carries a fin to enable some steering of the microrobot 100.

[0079] In this embodiment, the weight resonator 20, which is activated by the frequency of the propulsion spring 14, is carried by the hairs 24. More specifically, each hair 24 carries a weight resonator 20 which is activated at the appropriate activation frequency f A 、f A1 、f A2 The weight resonator 20 is activated below.

[0080] In this embodiment, at least one ciliary object 24 exhibits at least two stable states C A 、C B , each stable state C A 、C B In this way, each ciliary object 24 presents a first movement intensity I B The corresponding first stable state C B The first stable state C B corresponds to the inactive state of the weight resonator 20 carried by the hair-like object 24, and therefore corresponds to the inactive steering state B. The second stable state C A Corresponding to the second exercise intensity I A , and thus corresponds to the activated turning state A. The second movement intensity I A Higher than the first exercise intensity I B . In the first stable state C B All the ciliary bodies 24 move with the same first motion intensity I BOnce one (or more) cilia 24 are activated, it (they) will start to move with different intensities (second movement intensity I A ) moves, thereby causing a disruption to the overall symmetry of the microrobot 100, resulting in imbalance and ultimately a change in direction.

[0081] Functioning

[0082] As described above, for each embodiment, activation of the weight resonator 20 causes the elongated resonant structure 16 to enter at least one of its activated steering states A, A1, and A2. On the other hand, deactivation of the weight resonator 20 causes the elongated resonant structure 16 to enter its inactivated steering state B.

[0083] When the elongated resonant structure 16 is in the inactive steering state B, the propulsion direction of the microrobot 100 remains unchanged, and the microrobot 100 moves straight forward along the propulsion axis X. However, when the elongated resonant structure 16 enters at least one of its active steering states A, A1, A2, the microrobot 100 rotates and changes its propulsion direction.

[0084] Consider the first embodiment ( Figure 1a 、 Figure 2a 、 Figure 3a 、 Figure 4 ), the vibration of the propulsion spring 14 induces the microrobot 100 to vibrate at a given frequency. When the microrobot 100 vibrates at an appropriate activation resonance frequency f of one of the weight resonators 20 of the elongated resonant structure 16 A When vibrating, the weight resonator 20 under consideration begins to vibrate. This vibration induces its associated pre-compression beam 22a to move from its inactive configuration C B Changes to its active configuration C A The configuration change causes the associated steering fins 18 to deploy. The elongated resonant structure 16 is in its steering active state A. The deployment of the steering fins 18 triggers the rotation of the microrobot 100 and the redefinition of the propulsion direction X (see Figure 6 ). When the vibration of the microrobot 100 is lower than the given deactivation frequency f of the weight resonator 20 B When the weight resonator 20 is deactivated, the pre-compression beam 22 returns to its inactive configuration C B The steering vanes 18 are thus retracted and the elongated resonant structure 16 returns to its inactive steering state B. The frequency and / or amplitude of the motor 12 changes from one resonant frequency associated with a particular state to another resonant frequency associated with another state.

[0085] For the second embodiment ( Figure 1b 、 Figure 2b 、 Figure 3b ), which operates similarly to the aforementioned embodiment, except that the vibration of the propulsion spring 14 directly activates the multistable shell 22b, thereby changing the configuration and causing the microrobot 100 to rotate.

[0086] Regarding the fourth embodiment ( Figure 5a 、 Figure 5b 、 Figure 5c 、 Figure 6 ), it must be clear that each hair-like object 24 vibrates at a given intensity, and the vibration is caused by the vibration of the vibration motor (actuator) 12 of the microrobot 100. When the microrobot 100 is at an appropriate activation resonance frequency f of one of the weight resonators 20 of the elongated resonant structure 16, the microrobot 100 is vibrated at a given intensity. A When vibrating, the weight resonator 20 under consideration begins to vibrate. This vibration induces a change in the configuration of its associated strand of spring 140, more precisely its length, from the value that defines its inactive state C B The second length L B Change to define its activation state C A The first length L A This change in length leads to a destruction of the overall symmetry of the main body 101 of the microrobot 100, and the vibration axis of at least one of the cilia 24 is offset, thereby causing the microrobot 100 to rotate (see Figure 6 ).

[0087] Regarding the last example ( Figure 7a 、 Figure 7b 、 Figure 7c and Figure 8 ), when the microrobot 100 is activated at an appropriate resonant frequency f of one of the weight resonators 20 of the elongated resonant structure 16 A When vibrating, the weight resonator 20 under consideration begins to vibrate. This vibration induces a configuration change in the vibration intensity of the associated cilia 24. The cilia 24 then changes from its first motion intensity I B (corresponding to the turning inactive state B of the elongated resonant structure 16) into its motion intensity I A (Corresponding to the turned activated state A of the elongated resonant structure 16.) Thus, the activated cilium 24 vibrates at a different speed and amplitude than the other cilium 24 (or a series of outer flagella or cilia 15), thereby inducing rotation of the microrobot 100 (see FIG. 7).

[0088] The rotation of the microrobot 100 is likely achieved through a series of vibrations, resulting in a discrete accumulation of several small rotational movements to achieve the desired final rotation. This achieves a higher level of precision and safety.

[0089] It is much easier and more reliable to manage the three-dimensional orientation of the device using the fact that only a linear actuator whose activation frequency can be changed from a distance by the user, giving a solution in a two-dimensional plane (one axis = frequency, one axis = intensity) and only having to navigate on this plane to obtain the desired configuration.

Claims

1. A microrobot (100) configured to move in a propulsion direction by vibration, The microrobot (100) includes a body (101) and an actuator (12), wherein the body (101) is configured to vibrate, and the actuator (12) is configured to generate vibrations that move the microrobot (100). The microrobot (100) further includes a steering system (10), the steering system including a resonant structure (16) configured to be fixed to the microrobot (100), the resonant structure (16) including: - a steering structure (18) intended to control the direction of propulsion, - distributed weight resonators (20), each weight resonator (20) being configured to be activated by an appropriate resonant frequency (A, f A1 、f A2 ) is activated, the weight resonator (20) has a suitable activation resonance frequency (f A 、f A1 、f A2 ) are different from each other, wherein the actuator (12) is configured to generate vibrations within a frequency range that includes a suitable activation resonant frequency of each weight resonator, Wherein, the resonant structure (16) has at least two states: - at least one activation steering state (A, A1, A2) in which at least one of the weight resonators is activated at the appropriate activation resonance frequency to change the propulsion direction of the microrobot (100), - a non-activated steering state (B), in which no weight resonator is activated at its appropriate activation resonance frequency, thereby maintaining the propulsion direction of the microrobot (100).

2. The microrobot (100) according to the preceding claim, wherein The resonant structure (16) has several activation steering states (A1, A2), each activation steering state (A1, A2) associated with a different appropriate activation resonance frequency (f A1 、f A2 ) is associated with.

3. The microrobot (100) according to any one of the preceding claims, wherein: - the at least one activated steering state (A, A1, A2) is a state in which the configuration and movement of the resonant structure (16) are intended to change the propulsion direction of the microrobot (100), The inactive steering state (B) is a state in which the configuration and movement of the resonant structure (16) are intended to maintain the propulsion direction of the microrobot (100).

4. The microrobot (100) according to any one of the preceding claims, wherein: The resonant structure (16) further comprises distributed multistable elements (22), each multistable element (22) being capable of deforming between at least two stable configurations: - at least a first stable configuration (C) when the resonant structure (16) is in its activated steering state (A) A ), - at least a second stable configuration (C) when the resonant structure (16) is in its inactive steering state (B) B ).

5. The microrobot (100) according to the preceding claim, wherein Each multi-stable element (22) has a first stable configuration and a second stable configuration (C A 、C B ) of a bistable pre-compression beam (22), wherein the pre-compression beam (22) is in the first stable configuration (C A ) is bent in a first direction toward the main body (101) of the microrobot (100), and in a second stable configuration (C B ) is bent along a second direction away from the main body (101) of the micro robot (100).

6. The microrobot (100) according to any one of the preceding claims, wherein: The steering structure (18) is a retractable steering wing (18), which has an expanded configuration and a retracted configuration relative to the main body (101) of the micro robot (100), and the configuration of the steering wing (18) is determined by the steering state (A, A1, A2, B) of the resonant structure (16): - the inactive steering state (B) of the resonant structure (16) triggers the retracted configuration of the retractable steering flap (18), and - the activated steering state (A, A1, A2) of the resonant structure (16) triggers the deployed configuration of the retractable steering flap (18).

7. The microrobot (100) according to claim 4, wherein: Each multistable element (22) is a multistable shell (22) comprising a stack of several sheets.

8. The microrobot (100) according to any one of the preceding claims, wherein: The steering system (10) further includes at least one mobile hair-like object (24), and the at least one hair-like object (24) is configured to move by vibration of the main body (101) of the microrobot (100).

9. The microrobot (100) according to the preceding claim, wherein The resonant structure (16) includes at least one strand of a propulsion spring (14) contained within the body (101).

10. The microrobot (100) according to the preceding claim, wherein Activating the resonant structure (16) to its at least one activated steering state (A, A1, A2) causes retraction of at least one strand of the propulsion spring (14).

11. The microrobot (100) according to claim 9 or 10, wherein: The body (101) of the microrobot (10) exhibits overall circular symmetry about a propulsion axis parallel to the propulsion direction, wherein the resonant structure (16) is another part of the body (101), and wherein activation of the resonant structure (16) to one of its activated steering states (A, A1, A2) causes a disruption of the overall circular symmetry of the body (101).

12. The microrobot (100) according to claim 8, wherein: The at least one ciliary member (24) is a part of the resonant structure (16), and the at least one ciliary member (24) exhibits a first motion intensity (I) in the inactive steering state (B). B ) and presents a second motion intensity (I A ), the second exercise intensity (I A ) is different from the first exercise intensity (I B ).

13. The microrobot (100) according to the preceding claim, wherein Each ciliary organ (24) includes a weight resonator (20).

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