Pressure and impulse sensor

Abstract

The invention relates to a pressure and impulse sensor, and belongs to the technical field of mechanical sensors. The device comprises a substrate, a transition metal chalcogenide, a source electrode, a drain electrode, a flexible polymer material, a gate electrode and a packaging material, a transition metal chalcogenide is used as a channel layer, a flexible polymer material is used as a gate dielectric layer, and a field effect transistor is formed. The source electrode and the drain electrode are located at the two ends of the transition metal chalcogenide layer and are electrically communicated with the transition metal chalcogenide layer. According to the invention, the vertical electric field intensity in the gate dielectric layer is changed by using the stress-strain characteristics of the flexible high polymer material, so that the energy band structure of the channel material and the change of the output current are changed, and the sensing of pressure and impulse is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electronic components, and particularly to a pressure and impulse sensor. BACKGROUND

[0002] Mechanical sensors play an important role in many fields such as industrial production, electronic information, medical health, etc. With the development of nanomaterials and sensing technology, mechanical sensors are developing towards smaller size, lower energy consumption and more accurate response. Among them, two-dimensional transition metal dichalcogenide (2D-FET) sensors have shown strong competitiveness in terms of size and energy consumption, and have the potential to achieve nanoscale effective pressure sensing resolution. Compared with traditional force sensors, 2D-FET has extremely high micro-force response and extremely low power consumption requirements due to its small size. FET sensors use semiconductor channel electron structure changes to detect external stimuli, and have the advantages of high sensitivity and fast response speed.

[0003] Although a series of micro-force sensors and micro-force sensor arrays have been developed based on two-dimensional semiconductor material field effect transistors, they all have the advantages of small size and sensitive response. However, due to material or structural reasons, most of them lack durability and reliability. In addition, they cannot monitor impact force, i.e. impulse effect. Impulse is a process function that reflects the accumulation effect of force over time. SUMMARY

[0004] Therefore, the present application provides a pressure and impulse sensor. The sensor uses transition metal dichalcogenide (TMDC) as the channel layer and flexible polymer material as the gate dielectric layer to form a field effect transistor. The stress and strain characteristics of the flexible polymer material are used to change the vertical electric field intensity in the gate dielectric layer, thereby causing changes in the electron structure in the channel, and achieving pressure and impulse sensing.

[0005] To achieve the above purpose, the present application provides a pressure and impulse sensor, which comprises a substrate 1, a transition metal dichalcogenide 2, a source electrode 3, a drain electrode 4, a flexible polymer material 5, a gate electrode 6 and a packaging material 7. The transition metal dichalcogenide 2 is located on the substrate 1, and the source electrode 3 and the drain electrode 4 are located at both ends of the transition metal dichalcogenide layer 2 and are in electrical communication with the transition metal dichalcogenide layer 2. The flexible polymer material layer 5 is located above the transition metal dichalcogenide layer 2, the source electrode 3 and the drain electrode 4, covering the surface of the transition metal dichalcogenide layer 2, and the gate electrode 6 is located on the upper surface of the flexible polymer material layer 5, and its vertical projection covers the transition metal dichalcogenide layer 2. The packaging material 7 is located above the gate electrode 6, covering the transition metal dichalcogenide 2, the source electrode 3, the drain electrode 4, the flexible polymer material 5 and the gate electrode 6.

[0006] Further, the substrate 1 is a high insulating medium material.

[0007] Further, the transition metal chalcogenide layer 2 is a material with a chemical formula of MX2, wherein M is one of Mo, W, Pt, Hf, Ti, Bi, Ga, Sn, and X is one of O, S, Se, and Te.

[0008] Further, the thickness of the transition metal chalcogenide layer 2 ranges from 0.5 to 50 nanometers.

[0009] Further, the flexible high polymer material 5 is a high insulating gate medium layer.

[0010] Further, the flexible high polymer material 5 can be linearly elastically deformed, non-linearly elastically deformed, or hysteresis elastically deformed within a certain range.

[0011] Further, the thickness of the flexible high polymer material layer 5 ranges from 1 to 400 nanometers.

[0012] Further, the material of the source electrode 3 and the drain electrode 4 is one of Ti, Au, Ni, and Pt, or a combination of two in any proportion.

[0013] Further, the encapsulating material 7 is a high insulating flexible material, and the thickness ranges from 1 to 200 nanometers.

[0014] The above technical solutions of the present application have the following beneficial technical effects:

[0015] (1) The present application uses the change of the electronic structure in the transition metal chalcogenide channel to respond to the load stimulus, and the response speed is fast.

[0016] (2) The present application uses the stress deformation of the flexible high polymer material to change the vertical electric field intensity in the gate medium layer, and has good robustness and extremely high response, with a response of up to 8000%.

[0017] (3) The gate medium layer in the present application can obtain sensors with different measurement ranges by using high polymer materials with different mechanical properties.

[0018] (4) The present application uses the stress-strain relaxation performance of the flexible high polymer material to realize impulse sensing and detect the accumulation effect of the load over time. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic diagram of the pressure and impulse sensor provided by the present application.

[0020] Figure 2 is an example diagram of the pressure sensing result of the sensor provided by the present application.

[0021] In the figure, 1 is a substrate, 2 is a transition metal chalcogenide, 3 is a source electrode, 4 is a drain electrode, 5 is a flexible polymer material, 6 is a gate electrode, and 7 is a packaging material. DETAILED DESCRIPTION

[0022] In order to make the objects, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application with reference to the specific embodiments and the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of the known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0023] The pressure and impulse sensor disclosed in the present application, as shown in the figure, comprises a substrate 1, a transition metal chalcogenide layer 2, a source electrode 3, a drain electrode 4, a flexible polymer material 5, a gate electrode 6 and a packaging material 7. The transition metal chalcogenide layer 2 is located on the substrate 1, the source electrode 3 and the drain electrode 4 are located at both ends of the transition metal chalcogenide layer 2 and are in electrical communication with the transition metal chalcogenide layer 2. The flexible polymer material layer 5 is located above the transition metal chalcogenide layer 2, the source electrode 3 and the drain electrode 4, covering the surface of the transition metal chalcogenide layer 2. The gate electrode 6 is located on the upper surface of the flexible polymer material layer 5, and its vertical projection covers the transition metal chalcogenide layer 2. The packaging material 7 is located above the gate electrode 6, covering the transition metal chalcogenide layer 2, the source electrode 3, the drain electrode 4, the flexible polymer material 5 and the gate electrode 6. Figure 1 The pressure and impulse sensor in the present application uses the transition metal chalcogenide 2 as the semiconductor channel layer and uses the flexible polymer material 5 as the insulating gate dielectric layer to form a top gate field effect transistor structure. The stress and strain characteristics of the flexible polymer material are used to change the vertical electric field intensity in the gate dielectric layer, and then the energy band structure of the channel material is changed, the output current change is outputted, and thus the change of the load intensity over time is reflected.

[0024] The flexible polymer material 5 as the insulating gate dielectric layer should have a high dielectric constant κ and can have linear elastic deformation, non-linear elastic deformation or hysteresis elastic deformation within a certain range.

[0025] The flexible polymer material 5 uses a flexible polymer film with a thickness of about 1-400 nanometers, such as a polymethyl methacrylate (PMMA) film, a polydimethylsiloxane (PDMS) film, a polyvinyl alcohol (PVA) film, a polycaprolactone (PCL) film and the like.

[0026]

[0027] ​The transition metal chalcogenide layer 2 is a two-dimensional transition metal chalcogenide film with a thickness of about 0.5-50 nm, such as tungsten selenide, molybdenum selenide, platinum selenide, molybdenum sulfide, tungsten sulfide, platinum sulfide, or tungsten telluride, molybdenum telluride, platinum telluride. The material of the source electrode and the drain electrode is one of Ti, Au, Ni, Pt, or a composite material of any two of them.

[0028] Since the transition metal chalcogenide is a thin film material and has stable physicochemical properties, the manufacturing process of the transition metal chalcogenide phototransistor can completely adopt the existing microelectronic process and has nothing special, which will not be described here.

[0029] The following are more specific examples:

[0030] Example 1

[0031] The device structure is as described above, wherein the substrate 1 is silicon dioxide, the transition metal chalcogenide 2 is molybdenum disulfide, the flexible high polymer material 5 is PMMA, and the encapsulating material 7 is PVA. A load of 33 mN is repeatedly applied directly above the sensor, the gate voltage is kept at 1.5 V, and the reading voltage is set at 0.1 V; when no load is applied, the sensor current is about 0.3 μA, and when the load is applied, the sensor current is about 0.26 μA; the current data is converted into resistance value according to R=U / I, and the sensing response to the load is calculated to be about 8000% according to s=ΔR / R (as shown in Figure 2 ).

[0032] Example 2

[0033] The device structure is as described above, wherein the substrate 1 is a sapphire sheet, the transition metal chalcogenide 2 is molybdenum disulfide, the flexible high polymer material 5 is PMMA, and the encapsulating material 7 is PDMS. A load of 33 mN is continuously applied directly above the sensor for 18 minutes, during which the transfer curve of the sensor is scanned, the gate voltage is scanned in the range of−1.5-1.5 V, and the bias voltage is kept at 0.1 V; the load is removed, and the transfer curve of the sensor is continuously scanned for 20 minutes, the gate voltage is scanned in the range of−1.5-1.5 V, and the bias voltage is kept at 0.1 V; the current value at the same gate voltage is taken to make a current-time curve; when the load is continuously applied, the curve fitting equation is , wherein is the drain-source current, , is a constant, and the loading time can be expressed as ; according to the impulse equation , the impulse can be expressed as , therefore, the size and direction of the impulse can be obtained according to the size and direction of the loading force and the drain-source current signal collected by the sensor.

[0034] In summary, the present application provides a pressure and impulse sensor. The present application uses a transition metal chalcogenide channel layer and a flexible high polymer material gate dielectric layer to form a field effect transistor sensor, which can perform pressure sensing with a response of 8000%, and can also perform impulse sensing.

Claims

1. A pressure and impulse sensor, characterized in that, The material includes a substrate (1), a transition metal chalcogenide (2), a source electrode (3), a drain electrode (4), a flexible polymer material (5), a gate electrode (6), and an encapsulation material (7). The transition metal chalcogenide (2) is located on the substrate (1), and the source electrode (3) and drain electrode (4) are located at both ends of the transition metal chalcogenide layer (2) and are electrically connected to the transition metal chalcogenide layer (2). The flexible polymer material layer (5) is located above the transition metal chalcogenide layer (2), the source electrode (3), and the drain electrode (4), covering the transition metal chalcogenide layer. On the surface of the compound layer (2), the gate electrode (6) is located on the upper surface of the flexible polymer material layer (5), and its vertical projection covers the transition metal chalcogenide compound layer (2). The encapsulation material (7) is located above the gate electrode (6) and covers the transition metal chalcogenide compound (2), the source electrode (3), the drain electrode (4), the flexible polymer material (5), and the gate electrode (6). The flexible polymer material (5) can undergo linear elastic deformation, non-linear elastic deformation, or viscoelastic deformation within a certain range. The thickness of the flexible polymer material (5) ranges from 1 to 400 nanometers.

2. A pressure and impulse sensor according to claim 1, characterized in that, The transition metal chalcogenide layer (2) is a material with the chemical formula MX2, wherein M is one of Mo, W, Pt, Hf, Ti, Bi, Ga, Sn, and X is one of O, S, Se, Te; the thickness of the transition metal chalcogenide layer (2) ranges from 0.5 to 50 nanometers.

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