A multi-point proximity sensing network system based on electrostatic induction mechanism

Abstract

The present invention belongs to the technical field of instrumentation, and specifically is a multi-point proximity sensing network system based on an electrostatic induction mechanism. The system of the present invention includes: a DC voltage source, an ammeter, a transistor, and a signal line with a shielding layer; the voltage source is used to apply a source-drain bias to the transistor; the ammeter is used to test the channel current under the source-drain bias of the transistor; the signal line is arranged according to the sensing position requirements, and the shielding layer is partially broken at the position where proximity sensing detection is required to expose the internal signal line as a sensing end; all shielding layers are grounded, and all internal signal lines are electrically connected to the gate end of the transistor. When the object to be measured approaches or moves away from any sensing end, the electrostatic induction effect causes the induced potential on the gate of the transistor to change, thereby confirming the approach of the object to be measured. The present invention only uses one transistor combined with a reasonable wiring design to realize a network structure with a multi-point sensing function, avoiding the shortcomings of the solution of using multiple transistors to realize multi-point sensing.

Description

Technical Field

[0001] The invention belongs to the technical field of instruments and meters, and in particular relates to a multi-point proximity sensor network system based on an electrostatic induction mechanism. Background Art

[0002] Proximity sensing is a type of non-contact sensing mode. Before the object to be measured physically contacts the sensor, it can sense the approach of the object to be measured through long-range physical action. In a human-computer interaction environment, it can be used to avoid damage caused by physical collision between the robot and people or other surrounding environments. Common proximity sensing designs can be based on optical, ultrasonic, capacitive, magnetic field and electrostatic mechanisms. Based on long-range electrostatic induction, the applicant previously applied for two invention patents, "A surface potential measurement method based on an extended gate transistor structure" (application number 201910733844.X) and "A non-contact real-time electrostatic monitoring method based on an extended gate transistor" (application number 202010153268.4), which can be used for proximity sensing and surface potential measurement. However, the two patents are only applicable to proximity sensing detection at specific locations and do not have multi-point proximity sensing functions. Based on the above two patents, the present invention has developed a simple and easy-to-operate transistor-based multi-point proximity sensing network design method, which can realize the multi-point proximity sensing network function by using only one transistor and combining the reasonable layout of signal lines with a shielding layer. Summary of the invention

[0003] The object of the present invention is to provide a multi-point proximity sensing network system based on an electrostatic induction mechanism.

[0004] The present invention proposes a multi-point proximity sensor network system based on electrostatic induction mechanism, such as Figure 1 As shown, it specifically includes: a DC voltage source, an ammeter, a transistor, and a signal line with a shielding layer; wherein: the voltage source is used to apply a source-drain bias to the transistor; the ammeter is used to test the channel current under the source-drain bias of the transistor; the signal line with the shielding layer is arranged according to the sensing position requirements (such as m×n two-dimensional arrangement), and the shielding layer is partially broken at the position where the sensing detection is required to be close to the sensing detection, exposing the internal signal line as the sensing end (also known as the sensing unit); all shielding layers are grounded, and all internal signal lines are electrically connected to the gate end of the transistor. The exposed signal line serves as the sensing end to form a sensing network;

[0005] When the object to be measured approaches any sensing end, electrostatic induction causes the induced potential on the transistor gate to change, which causes the transistor threshold voltage to drift, that is, causes the transistor source-drain current to change, thereby detecting the approach of the object to be measured.

[0006] In the system, a certain distance is maintained between adjacent sensing ends, and the distance may be between 1 micrometer and 10 meters, preferably between 1 centimeter and 1 meter.

[0007] In this system, the length of the exposed internal signal line can be as short as 1 micron, and the diameter of the signal line can be as short as 1 micron.

[0008] In this system, the signal line in the shielding layer serves as the transmission line for the sensing signal and transmits the signal to the gate end of the transistor to regulate the source-drain current of the transistor and realize the proximity sensing function.

[0009] In this system, the transistors used can be various three-terminal structure devices with gate control functions, including but not limited to silicon transistors, oxide transistors, organic transistors, transistors constructed of two-dimensional materials, etc.

[0010] Partially breaking the shielding layers in the present invention means that the electrical connection between the shielding layers cannot be damaged after breaking, that is, ultimately all the shielding layers should be effectively grounded.

[0011] The present invention can realize a network structure with a multi-point sensing function by only using one transistor combined with a reasonable wiring design, thereby avoiding the shortcomings of a solution that usually uses multiple transistors to realize multi-point sensing.

[0012] The present invention has a simple structure and reliable accuracy, and can easily realize proximity sensing detection of multi-point networks. Combined with the applicant's previous invention patents "A surface potential measurement method based on an extended gate transistor structure" (application number 201910733844.X) and "A non-contact real-time electrostatic monitoring method based on an extended gate transistor" (application number 202010153268.4), the surface potential of the target object can be further measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a typical proximity sensor network layout with 4×4 sensor units in the present invention.

[0014] Figure 2 for Figure 1 Experimental test results of the 4×4 array proximity sensing network shown. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. The examples described herein are only a part of the present invention, rather than all the examples. At the same time, the examples are used to explain the present invention and are not used to limit the present invention.

[0016] Example 1

[0017] A typical layout method for a proximity sensing network with 4×4 sensing units. Conventional coaxial BNC cable is used as a signal cable with a shielding layer. The cable has a four-layer structure from the outside to the inside: rubber insulation layer / shielding braided mesh / plastic sleeve / core wire. Use a cutter to break the first three layers (rubber insulation layer / shielding braided mesh / plastic sleeve) at a specific position on the BNC cable until the inner core wire is exposed. The length of the exposed core wire is 3mm. When cutting the shielding insulation mesh, ensure that only the upper braided mesh is broken, and do not affect the electrical connection of the shielding layer on the entire cable. The shielding meshes of all BNC cables are connected together and effectively grounded, and all signal lines are electrically connected together and connected to the transistor gate. The exposed signal wire is used as the sensing end for proximity sensing detection. Figure 1 The numbers 1-16 shown are 4×4 sensor units constructed, and the distance between adjacent units is 50 cm.

[0018] The transistor used is an oxide transistor, in which the semiconductor layer is tungsten-doped indium oxide, the dielectric layer is 300nm thick SiO2, the gate electrode is n-type heavily doped silicon, the source and drain electrodes are conductive indium tin oxide films, and the channel region length and width are 60um and 0.5mm respectively.

[0019] Embodiment 2:

[0020] Based on the 4×4 proximity sensing network constructed in Example 1, the proximity sensing performance is explained. The source terminal of the transistor is grounded, and a constant DC bias of 10V is applied to the drain terminal. The object to be tested is a polytetrafluoroethylene (PTFE) rod with a diameter of 1 cm, which has not undergone any deliberate friction charging treatment before testing. During the test, an electrically controlled translation stage is used to control the PTFE rod to gradually approach a certain sensing end from a distance of 3 cm until the distance is reduced to 3 mm; then the PTFE rod is controlled to move away from the sensing end to a distance of 3 cm. During this process, the changes in the source and drain currents are recorded in real time. The PTFE rods are close to sensing ends 1, 7 and 9 in turn. Figure 2 The corresponding test results are shown in Figure 2. For the three sensing ends, obvious changes in source-drain current can be observed when the PTFE rod approaches or moves away from the sensor, thus realizing the multi-point proximity sensing function.

Claims

1. A multi-point proximity sensing network system based on electrostatic induction mechanism, characterized in that: Specifically include: DC voltage source, ammeter, transistor, signal line with shielding layer; among which: The voltage source is used to apply a source-drain bias voltage to the transistor; The ammeter is used to test the channel current under the source-drain bias of the transistor; The signal lines with shielding layers are arranged according to the requirements of the sensing position, and the shielding layers are partially broken at the position where proximity sensing detection is required to expose the internal signal lines as sensing ends; all shielding layers are grounded, and all internal signal lines are electrically connected to the gate end of the transistor; the exposed signal lines serve as sensing ends to form a sensing network; When the object to be measured approaches any of the sensing ends, the electrostatic induction effect causes the induced potential on the transistor gate to change, which causes the transistor threshold voltage to drift, that is, causes the transistor source-drain current to change, so that the approach of the object to be measured can be detected; The minimum length of the exposed internal signal line is 1 micron, and the minimum signal line diameter is 1 micron; The signal line in the shielding layer serves as a transmission line for the sensing signal and transmits the signal to the gate terminal of the transistor to regulate the source-drain current of the transistor and realize the proximity sensing function.

2. The multi-point proximity sensor network system according to claim 1, characterized in that: Keep a certain distance between adjacent sensing ends.

3. The multi-point proximity sensor network system according to claim 1, characterized in that: The transistor is a three-terminal structure device with various gate control functions, including silicon transistors, oxide transistors, organic transistors, and transistors constructed of two-dimensional materials.

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