Large area force sensor based on molecular electronic transducers and tube structures

Abstract

This disclosure provides a force sensor primarily used for vibration, contact, and force sensing in large areas of interest, featuring a small number of transducers. The disclosure includes a pressure transducer based on molecular electronic transducer technology, integrated with an elastic tube structure. This disclosure can be used to construct intelligent environments for applications such as robotic contact sensing and sleep monitoring.

Description

Technical Field

[0001] This disclosure relates to the field of sensors, and more specifically, to a large-area force sensor based on a molecular electronic transducer and a tube structure. Background Technology

[0002] One trend is the development of intelligent environments capable of adapting to human activity to facilitate human-environment interaction. This requires environments to be intelligent enough to sense and understand human presence and activity. Due to their versatility, the sensing of human activity has traditionally relied on long-range sensing, primarily cameras and radar. However, these have dead spots, limiting resolution and frame rates, as well as privacy concerns. Therefore, new sensors are needed.

[0003] Force sensors are devices that measure the physical interaction between objects in contact. They are widely used in industry and daily life, such as elevator buttons, robotic manipulators for grasping, and manufacturing performance testing. Similar to human touch, they are crucial for human-environment interaction. For example, in human-machine interaction, contact sensing via force sensors can improve worker safety in the workplace. This is a milestone for the future of smart manufacturing.

[0004] Low-cost, robust, and highly sensitive force sensors capable of covering large areas of interest can significantly improve the intelligence of living and working environments. Summary of the Invention

[0005] On one hand, this disclosure provides a force sensor, comprising: a tube and at least one first pressure transducer, wherein at least one end of the tube is connected to the first pressure transducer and the tube is filled with fluid; the first pressure transducer comprises: a housing; a first elastic membrane and a second elastic membrane disposed opposite to each other on both sides of the housing, the first elastic membrane and the second elastic membrane forming a closed space with the housing, and the tube being connected to the first pressure transducer through the second elastic membrane; an electrolyte disposed within the closed space; and a plurality of porous electrodes within the closed space, which are stacked and spaced apart from each other by porous dielectric spacers, wherein the normals of the first elastic membrane, the normals of the second elastic membrane, the holes on the porous electrodes, and the holes of the porous dielectric spacers are aligned.

[0006] In one embodiment, the first pressure transducer is a pressure transducer based on a molecular electronic transducer.

[0007] In one embodiment, the force sensor further includes a second pressure transducer disposed in the tube, wherein the second pressure transducer includes: a third elastic membrane and a second elastic membrane disposed opposite to each other; an electrolyte droplet; encapsulating oil disposed on opposite sides of the electrolyte droplet and in contact with the second elastic membrane and the third elastic membrane respectively; and at least two electrode pairs arranged side by side along a direction from the third elastic membrane to the second elastic membrane.

[0008] In one embodiment, the force sensor is configured to contact the surface of the structure under test, and the tube is arranged around the first pressure transducer across the surface of the structure under test.

[0009] In one embodiment, the force sensor is disposed inside the structure under test, and the tube is arranged inside the structure under test around the first pressure transducer to span the surface in contact with the structure under test.

[0010] In one embodiment, one end of the tube is connected to the first pressure transducer, and the other end is sealed.

[0011] In one embodiment, the at least one first pressure transducer includes a plurality of first pressure transducers, and the two ends of the tube are respectively connected to two of the first pressure transducers.

[0012] In an embodiment, the at least one first pressure transducer includes a plurality of first pressure transducers arranged along a first direction, the tube includes a first tube connected to a portion of the plurality of first pressure transducers and a second tube connected to the remaining portion of the plurality of first pressure transducers, the other ends of the first tube and the second tube are sealed, the first tube extends along a second direction intersecting the first direction, and the second tube extends along the second direction and the first direction, such that the first tube and the second tube intersect to form a mesh pattern.

[0013] In one embodiment, the structure to be tested is disposed at the mesh pattern, and at the intersection of the mesh pattern, the second tube is in contact with the surface of the structure to be tested, and the first tube is disposed on the side of the second tube opposite to the structure to be tested.

[0014] In an embodiment, the rigidity of the first tube and the second tube at the mesh pattern is less than the rigidity of the first tube and the second tube at other locations.

[0015] In an embodiment, each of the at least two electrode pairs includes a cathode and an anode disposed opposite each other.

[0016] On the other hand, this disclosure also provides a force sensing system, including: a force sensor, wherein the force sensor is a force sensor according to an embodiment of this disclosure; and

[0017] A supporting plywood is provided, wherein the tube of the force sensor is disposed between the bottom surface of the mattress to be tested and the supporting plywood, the tube is filled with silicone oil, and the tube is arranged in a spiral pattern and spans the bottom surface of the mattress to be tested. Attached Figure Description

[0018] Figure 1 The structure and working principle of a force sensor according to an embodiment of the present disclosure are shown.

[0019] Figure 2 The structure and operating principle of another force sensor according to an embodiment of the present disclosure are shown.

[0020] Figure 3 The arrangement of a force sensor located on the surface of a structure according to an embodiment of the present disclosure is shown.

[0021] Figure 4 The configuration of a force sensor embedded in a structure according to an embodiment of the present disclosure is shown.

[0022] Figure 5 A configuration of a force sensor having at least two pressure transducers based on molecular electron transducers (MET) for position sensing of force is shown according to an embodiment of the present disclosure.

[0023] Figure 6 A configuration of a matrix-arranged force sensor for a force mapping application, according to an embodiment of the present disclosure, is shown.

[0024] Figure 7 A force sensor in a sleep monitoring application according to an embodiment of the present disclosure is shown. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] This disclosure relates to a force sensor primarily used for vibration, contact, and force sensing in a large region of interest with a small number of transducers.

[0027] This disclosure relates to a molecular electron transducer (MET) that can convert liquid motion into electronic signals based on the movement of a conductive electrolyte and through an electrochemical reaction.

[0028] refer to Figure 1Embodiments of this disclosure provide a force sensor 100, including at least one MET-based pressure transducer 101 (hereinafter referred to as a MET pressure transducer) and a fluid-filled tube 102 connected to the pressure transducer 101. The other end of the tube 102 may be sealed. The MET pressure transducer 101 includes a housing 110, an electrolyte 111, a plurality (e.g., at least two) of elastic membranes 112 and 113, a plurality (e.g., at least four) of porous electrodes 114 to 117, and porous dielectric spacers 118 separating the porous electrodes 114 to 117. In an embodiment, the elastic membranes 112 and 113 together with the housing 110 form a sealed space, and the tube 102 is connected to the pressure transducer 101 through the elastic membranes 113. The normals of the elastic membranes 112 and 113, the holes on the porous electrodes 114 to 117, and the holes on the porous dielectric spacers 118 may be aligned.

[0029] During operation, force 131 acts on tube 102, inducing deformation, pressure, and flow within tube 102. The pressure is transmitted to the MET pressure transducer 101 to deform the elastic membrane 113. The deformation of the elastic membrane 113 results in deformation, and the pressure and stressed electrolyte within the housing 110 flows through the porous electrodes 114 to 117 and the porous dielectric spacer 118. An elastic membrane 112 may be located on the opposite side of the elastic membrane 113 to allow for liquid movement. Therefore, the elastic membrane 112 deforms in response to the deformation of the elastic membrane 113. The flow of electrolyte can be measured by the difference between the electrochemical reaction currents of at least two of the porous electrodes 114 to 117.

[0030] refer to Figure 2 Embodiments of this disclosure provide a force sensor 200, including at least one MET pressure transducer 201 and a fluid-filled tube 202 connected to the pressure transducer 201. The other end of the tube 202 may be sealed. The MET pressure transducer 201 includes a housing 210, an electrolyte 211, a plurality (e.g., at least two) of elastic membranes 212 and 213, a plurality (e.g., at least four) of porous electrodes 214 to 217, and porous dielectric spacers 218 separating the porous electrodes 214 to 217. The normals of the elastic membranes 212 and 213, the holes on the porous electrodes 214 to 217, and the holes on the porous dielectric spacers 218 may be aligned.

[0031] In an embodiment, the force sensor 200 may further include a transducer 205 sensitive to constant pressure. The transducer 205 may consist of at least two elastic membranes 213 and 253, encapsulating oil 252, electrolyte droplets 251, and at least two electrode pairs 254 and 255. In an embodiment, transducers 201 and 205 share the elastic membrane 213. In an embodiment, each of the electrode pairs 254 and 255 consists of at least an anode and a cathode of equal length, and the electrode pairs 254 and 255 are arranged side-by-side. The cathode and anode of each electrode pair are positioned opposite each other.

[0032] During operation, in the absence of force 231, the electrolyte droplet 251 is stationary, and the contact surface area between the electrolyte droplet 251 and electrode pairs 254 and 255 is equal. Therefore, the current between electrode pairs 254 and 255 is equal. The force 231 acting on tube 202 generates deformation, pressure, and flow inside tube 202. The pressure is first transmitted to transducer 205, causing deformation of elastic membrane 253. The deformation of membrane 253 translates into a change in volume and propels the electrolyte droplet 251 to a new position. The contact surface area between electrolyte droplet 251 and electrode pair 254 increases, while the contact surface area between electrolyte droplet 251 and electrode pair 255 decreases. Therefore, the current difference between electrode pairs 254 and 255 can be measured to represent the static pressure in tube 202. The deformation of elastic membrane 253 causes deformation of elastic membrane 213. Deformation of the elastic membrane 213 causes deformation, and the pressure and force of the electrolyte within the housing 210 flow through the porous electrodes 214 to 217 and the porous dielectric spacer 218. The elastic membrane 212 may be located on the opposite side of the elastic membrane 213 to allow liquid movement. Therefore, the elastic membrane 212 deforms as the elastic membrane 213 deforms. The flow of electrolyte can be measured by the difference between the electrochemical reaction currents of at least two of the porous electrodes 214 to 217.

[0033] refer to Figure 3 A tube 302 can be disposed on the outer surface of structure 311 for force sensor 301 to measure vibrations of structure 311, as well as external forces applied to tube 302 before being applied to structure 311. At least one end of tube 302 can be connected to MET pressure transducer 308, while the other end of tube can be sealed. In an embodiment, the tube is arranged around MET pressure transducer 308 on the outer surface of the structure to span the contact surface with the structure.

[0034] refer to Figure 4The tube 302 can be configured to be embedded within the structure 311 for the force sensor 301 to measure vibrations of the structure 311, as well as external forces applied to the tube 302 after being applied to the structure 311. In an embodiment, the tube is arranged inside the structure around the MET pressure transducer 308 to span the contact surface with the structure. At least one end of the tube 302 can be connected to the MET pressure transducer 308, while the other end of the tube 302 can be sealed.

[0035] refer to Figure 5 The two ends of tube 402 can be connected to MET pressure transducers 408 and 409 of force sensor 301 to measure the position of external force 431. If force 431 is located at a distance of equidistant from distances 432 and 433, MET pressure transducers 408 and 409 generate signals simultaneously. If distance 432 is less than distance 433, MET pressure transducer 408 generates a signal earlier than MET pressure transducer 409. The position of force 431 can be obtained by comparing the phase of the signals.

[0036] refer to Figure 6 Tubes 522 and 523 can be configured in a matrix, meaning they can intersect to form a mesh pattern, allowing force sensor 501 to measure the vertical and horizontal positions of force 531 within the region of interest 535 (i.e., the mesh pattern). Within the region of interest 535, tube 522 can be configured horizontally, and tube 523 can be configured vertically. Tubes 522 and 523 can consist of a rigid portion 525 outside the region of interest 535 and a less rigid portion 524 inside the region of interest 535. Inside the region of interest 535, at the intersection of tubes 522 and 523, tube 522 can be located on top of structure 511, and tube 523 can be located on top of tube 522. One end of tubes 522 and 523 can be connected to the MET pressure transducer 508, while the other end is sealed.

[0037] In this example, force 531 is applied to the lower left intersection of tubes 522 and 523 within the region of interest 535. Signals can be transmitted by the first and fourth MET pressure transducers 508, counted from the left.

[0038] The force sensor provided in the embodiments of this disclosure can perform large-area vibration sensing, especially for sleep monitoring applications.

[0039] The device utilizing the force sensor of an embodiment of the present disclosure can monitor a user’s heart rate (BCG), cardiac stenography (SCG), respiratory rate, body movement and other mechanobiosignals in a non-invasive and inconspicuous manner in real time and continuously.

[0040] The force sensor using embodiments of this disclosure can convert mechanical biosignals from a top user, with the signal amplitude having low sensitivity to the relative distance between the user and a sensor using only one sensor.

[0041] The device can be placed under or embedded in a mattress, cushion, or other furniture, allowing the user to lie, sit, or stand on it. The device converts the user's mechanical biosignals into electrical signals. It automatically detects the user's presence and begins recording the converted electrical signals. These signals can be transmitted to a data acquisition unit via wired or wireless methods.

[0042] Figure 7 A bottom view showing an example placement of the force sensor of this disclosure is shown. Device 605 is placed beneath mattress 601. Device 605 consists of a support plywood 604, a high-sensitivity pressure sensor 603 (specifically a MET pressure sensor (i.e., a MET pressure transducer)), and a silicone rubber tube 602 filled with silicone oil. The silicone rubber tube 602 is sandwiched between mattress 601 and support plywood 604. The silicone rubber tube 602 is in contact with mattress 601 and secured to support plywood 604. One end of the silicone rubber tube 602 is connected to the MET pressure sensor 603, while the other end is sealed. The silicone rubber tube 602 is arranged in a spiral pattern, spanning the entire bottom surface of mattress 601. The MET pressure sensor 603 is horizontally embedded in support plywood 604, with its sensing axis parallel to the surface of mattress 601.

[0043] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A force sensor, comprising: The tube and at least one first pressure transducer, wherein, At least one end of the tube is connected to the first pressure transducer, and the tube is filled with fluid; The first pressure transducer includes: shell; A first elastic membrane and a second elastic membrane are disposed opposite to each other on both sides of the outer shell. The first elastic membrane and the second elastic membrane form a closed space with the outer shell, and the tube is connected to the first pressure transducer through the second elastic membrane. Electrolyte, which is disposed within the enclosed space; The enclosed space contains multiple porous electrodes, which are stacked and spaced apart by porous dielectric spacers. The normals of the first elastic membrane, the second elastic membrane, the holes on the porous electrode, and the holes in the porous dielectric spacer are aligned. The force sensor further includes a second pressure transducer disposed within the tube, wherein the second pressure transducer comprises: The third elastic membrane and the second elastic membrane are arranged opposite to each other; Electrolyte droplets; Encapsulation oil disposed on opposite sides of the electrolyte droplets and in contact with the second and third elastic membranes, respectively; and At least two electrode pairs are arranged side by side along the direction from the third elastic membrane to the second elastic membrane.

2. The force sensor according to claim 1, wherein... The first pressure transducer is a pressure transducer based on a molecular electronic transducer.

3. The force sensor according to claim 2, wherein, The force sensor is configured to contact the surface of the structure to be measured. The tube is arranged around the first pressure transducer across the surface of the structure under test.

4. The force sensor according to claim 2, wherein, The force sensor is installed inside the structure to be measured. The tube is arranged inside the structure under test around the first pressure transducer to span the surface in contact with the structure under test.

5. The force sensor according to claim 2, wherein, One end of the tube is connected to the first pressure transducer, and the other end is sealed.

6. The force sensor according to claim 2, wherein, The at least one first pressure transducer includes a plurality of first pressure transducers, and the two ends of the tube are respectively connected to two first pressure transducers.

7. The force sensor according to claim 1, wherein... Each of the at least two electrode pairs includes a cathode and an anode disposed opposite each other.

8. A force sensor, comprising: The tube and at least one first pressure transducer, wherein, At least one end of the tube is connected to the first pressure transducer, and the tube is filled with fluid; The first pressure transducer includes: shell; A first elastic membrane and a second elastic membrane are disposed opposite to each other on both sides of the outer shell. The first elastic membrane and the second elastic membrane form a closed space with the outer shell, and the tube is connected to the first pressure transducer through the second elastic membrane. Electrolyte, which is disposed within the enclosed space; The enclosed space contains multiple porous electrodes, which are stacked and spaced apart by porous dielectric spacers. The normals of the first elastic membrane, the second elastic membrane, the holes on the porous electrode, and the holes in the porous dielectric spacer are aligned. Wherein, the at least one first pressure transducer includes a plurality of first pressure transducers arranged along a first direction. The tube includes a first tube connected to a portion of the plurality of first pressure transducers and a second tube connected to the remaining portions of the plurality of first pressure transducers, the other ends of the first tube and the second tube being sealed. The first tube extends along a second direction that intersects the first direction, and the second tube extends along both the second and first directions, such that the first and second tubes intersect to form a mesh pattern.

9. The force sensor according to claim 8, wherein, The structure to be tested is positioned at the mesh pattern. At the intersection of the mesh pattern, the second tube contacts the surface of the structure under test, and the first tube is disposed on the side of the second tube away from the structure under test.

10. The force sensor according to claim 9, wherein The rigidity of the first tube and the second tube at the mesh pattern is less than that of the first tube and the second tube at other locations.

11. A force sensing system, comprising: A force sensor, wherein the force sensor is the force sensor according to claim 1; and Supporting plywood, among which, The force sensor tube is positioned between the bottom surface of the mattress to be tested and the supporting plywood. The tube is filled with silicone oil and is arranged in a spiral pattern across the bottom surface of the mattress under test.

Images