TWI442035B - Pressure sensor and sensing array - Google Patents

Description

Pressure sensor and sensing array

The present invention relates to a pressure sensor and a sensing array, and more particularly to a pressure sensor and sensing array with a variable sensing range.

Generally, the pressure sensor converts a pressure source acting on the sensing element into a voltage signal, and the voltage signal is further amplified by a analog/digital conversion amplifier and converted into a digital signal, and the digital signal is further processed by a processor. Judging to sense the pressure value.

Since the traditional pressure sensor is only suitable for a single sensing range, when the pressure value to be measured exceeds the range that the pressure sensor can withstand, it must be replaced with another pressure sensing that can withstand a large pressure range. This makes the current range of pressure sensors limited.

It is an object of the present invention to provide a pressure sensing range that can control or adjust the pressure sensor.

Another object of the present invention is to provide a pressure sensor or pressure sensing array that can be applied to a variety of different applications.

To achieve the above and other objects, the pressure sensor of the present invention comprises: a sensing range modulation structure comprising an upper control electrode, a carbon nanotube-liquid crystal composite layer, and a lower control electrode. a clamping structure for adjusting a direction angle of the carbon nanotube-liquid crystal composite material according to electrical control of the upper control electrode and the lower control electrode; a protective film layer covering the sensing range modulation structure And contacting the upper control electrode; a substrate is disposed under the sensing range modulation structure to clamp the sensing range modulation structure between the protective film layer and the substrate, and the substrate contacts the lower control electrode Wherein, the electrical measurement result of the lower control electrode is used for obtaining a pressure sensing value; and a spacer layer is interposed between the protective film layer and the substrate to space the sensing The range modulation structure is an accommodation space between the protective film layer and the substrate.

To achieve the above and other objects, the pressure sensing array of the present invention comprises: a plurality of sensing range modulation structures, each of which comprises an upper control electrode, a carbon nanotube-liquid crystal composite layer, And a pinch structure composed of the control electrode to adjust the direction angle of the carbon nanotube-liquid crystal composite material according to the electrical control of the upper control electrode and the lower control electrode; a protective film layer covering the same Sensing the range modulation structure and contacting the upper control electrodes; a substrate is disposed under the sensing range modulation structures to clamp the sensing range modulation structures between the protective film layer and the substrate The substrate is in contact with the lower control electrodes, wherein a pressure sensing result is obtained by electrical measurement results of each lower control electrode; and a spacer layer is clamped to the protective film layer and the Between the substrates, the plurality of accommodation spaces between the protective film layer and the substrate are modulated by spacing the sensing ranges.

In one embodiment, the spacer layer can be made of a polymer material, such as polydimethyl siloxane.

In one embodiment, the protective film layer may be a soft conductive plastic film, and the conductive plastic film may be a polyester film.

In one embodiment, the thickness of the protective film layer may be 90-110 micrometers, the thickness of the substrate may be 630-770 micrometers, and the thickness of the spacer layer may be 450-550 micrometers, each of which may be The thickness of the control electrode and each of the lower control electrodes may each be 108 to 132 nm.

In one embodiment, the protective film layer has a thickness of 100 μm, the substrate has a thickness of 700 μm, and the spacer layer has a thickness of 500 μm, each of the upper control electrode and each of the lower control electrodes. The thickness is 120 nm each.

Thereby, the pressure sensor and the pressure sensing array of the present invention utilize a composite material in which a carbon nanotube and a liquid crystal molecule are mixed as a sensing material, thereby achieving various resistance values by further angular rotation control, so that the present invention The sensor can adjust the sensing range of the pressure sensor by electrical control, and the pressure sensor different from the fixed sensing range of the prior art can be widely applied to various sensors. Pressure sensing occasions.

In order to fully understand the objects, features and advantages of the present invention, the present invention will be described in detail by the accompanying drawings. The thickness of each layer of the structure is only an example. In the drawings, the thickness ratio between the layers is not an actual ratio.

First, please refer to Fig. 1, which is a cross-sectional view of a pressure sensor in an embodiment of the present invention. The pressure sensor includes: a sensing range modulation structure 200, a protective film layer 110, a substrate 120, and a spacer layer 130.

The sensing range modulation structure 200 includes a squeezing structure composed of an upper control electrode 210, a carbon nanotube-liquid crystal composite material layer 220, and a lower control electrode 230, and the squeezing structure can be Electrical control of the upper control electrode 210 and the lower control electrode 230, for example, generating an electric field or a magnetic field between the squeezing structures, that is, controlling the steering angle of the liquid crystal molecules and adjusting the direction angle of the carbon nanotube-liquid crystal composite material . Different resistance values will be correspondingly produced as the orientation angle of the carbon nanotube-liquid crystal composite is different, as will be described in more detail later.

The protective film layer 110 covers the sensing range modulation structure 200, and the protective film layer 110 contacts the upper control electrode 210. The substrate 120 is located below the sensing range modulation structure 200 to sandwich the sensing range modulation structure 200 between the protective film layer 110 and the substrate 120, and the substrate 120 contacts the lower control electrode 230. The electrical measurement of the lower control electrode 230 can utilize the electrical measurement result to obtain a pressure sensing value. For example, as the external force applied to the protective film layer 110 increases, the sensing range modulation structure 200 will be compressed to reduce its internal resistance value, by the configuration of the upper control electrode 210, the lower control electrode 230, and the wires. The resistance value that can be changed between them can be obtained, and the pressure sensing value can be converted. The substrate 120 can be a conductive glass.

The spacer layer 130 is interposed between the protective film layer 110 and the substrate 120 to space the accommodation space of the sensing range modulation structure 200, and the carbon nanotube-liquid crystal composite material can be stored in the receiving space. Within the space.

In the embodiment of the present invention, the spacer layer 130 is preferably made of a polymer material, for example, made of polydimethyl siloxane. The protective film layer 110 is preferably a conductive plastic film, such as a polyester film.

2A to 2C are diagrams showing the modulation of the sensing range in the embodiment of the present invention. The currently known carbon nanotube-liquid crystal composite material disperses the carbon nanotubes in the liquid crystal material, and the atomic attraction between them is caused by the attraction between the carbon tubes and the liquid crystal molecules, thereby causing the average of the carbon tubes. The pointing direction will be indirectly controlled by the control of the direction of the liquid crystal molecules. In the embodiment of the present invention, this characteristic is applied to pressure sensing, and an electric field or a magnetic field is used to control the direction angle of the carbon nanotubes to adjust the resistance values of different sensing ranges.

As shown in FIGS. 2A to 2C, the larger the driving voltage applied between the sensing range modulation structures 200, the larger the angle at which the liquid crystal molecules rotate, and the larger the angle of the carbon tubes. Since the direction of the carbon tube affects the conductive path, the conductive paths in FIGS. 2A to 2C are all different, which will cause the resistance value between the sensing range modulation structures 200 to depend on the angle of the carbon tube. The driving voltage applied in Fig. 2A is 0. In Fig. 2B, a small amount of voltage is applied, and in Fig. 2C, a large voltage is applied. Therefore, the resistance of the sensing range modulation structure 200 will decrease as the angle of the carbon tube increases.

When the sensing range modulation structure 200 is subjected to the external force F, the carbon tubes will approach each other to cause a decrease in the resistance value, and thus the pressure sensing of the present invention is performed in this manner. In addition, the higher the initial resistance value when the sensing range modulation structure 200 is not subjected to an external force, the greater the pressure that can be withstood, and the sensed pressure range may be initially determined by the sensing range modulation structure 200. The resistance values vary. Since the interception of the measurement signal on the circuit has a fixed range, the area a in the 2A to 2C diagram is a pressure range sensible under the driving voltage of the sensing range modulation structure 200.

Next, please refer to FIG. 3, which is a pressure-resistance diagram of the pressure sensor in the embodiment of the present invention. As can be seen from the figure, under three different driving voltages, namely: 0.5V, 1V, 3V, the resistance decreases with the increase of external pressure, and has different initial resistance values with different driving voltages. The pressure sensor proposed by the embodiment of the invention can adjust the sensing range of the pressure by the control of the driving voltage. For example, when the driving voltage is low (0.5V), the rotation angle of the carbon tube is small and the resistance is large, and the upper limit of the pressure range that can be measured can reach 80 (kPa) or more.

Next, please refer to FIG. 4, which is a perspective view of a pressure sensing array in an embodiment of the present invention. The pressure sensing array 300 is extended based on the structure shown in FIG. 1 , and the entire sensing array is completed by the configuration of the plurality of sensing range modulation structures 200 . In Fig. 4, the overall structure is depicted in such a manner that the structures are offset from each other, and the upper control electrode 210 and the lower control electrode 230 are connected with wires for control.

The pressure sensor or pressure sensing array of the embodiments of the present invention can be fabricated by microelectromechanical technology. The upper and lower control electrodes 210 and 230 are respectively formed on the protective film layer 110 and the substrate 120, and then the spacer layer 130 is formed on the substrate 120 defining the lower control electrode 230 and the wires, and the spacer layer 130 is formed on the spacer layer 130. The accommodating space is defined for the filling of the carbon nanotube-liquid crystal composite material, and finally the protective film layer 110 defining the upper control electrode 210 and the wire is covered to complete the fabrication of the pressure sensor or the pressure sensing array.

In the above fabrication, the thickness of the protective film layer 110 may be 90-110 micrometers, the thickness of the substrate 120 may be 630-770 micrometers, and the thickness of the spacer layer 130 may be 450-550 micrometers, and the upper control electrode 210 and The thickness of the lower control electrode 230 may each be 108 to 132 nm. In a preferred embodiment, the thickness of the protective film layer 110 is 100 micrometers, the thickness of the substrate 120 is 700 micrometers, and the thickness of the spacer layer 130 is 500 micrometers. The upper control electrode 210 and the lower control electrode 230 are The thickness is 120 nm each.

In summary, the embodiments of the present invention provide a pressure sensor and a sensing array that are different from the simple fixed measurement range, so that the present invention can sense the driving angle of the liquid crystal molecules. The sensor has a wide range of sensing capabilities, which can greatly increase the range of applications of the pressure sensor.

The invention has been described above in terms of the preferred embodiments, and it should be understood by those skilled in the art that the present invention is not intended to limit the scope of the invention. It should be noted that variations and permutations equivalent to those of the embodiments are intended to be included within the scope of the present invention. Therefore, the scope of protection of the present invention is defined by the scope of the patent application.

110. . . Protective film

120. . . Base

130. . . Spacer layer

200. . . Sensing range modulation structure

210. . . Upper control electrode

220. . . Nano carbon tube - liquid crystal composite layer

230. . . Lower control electrode

300. . . Pressure sensing array

a. . . Sensible range

F. . . external force

R. . . resistance

Fig. 1 is a cross-sectional view showing a pressure sensor in an embodiment of the invention.

2A to 2C are schematic diagrams showing modulation of the sensing range in the embodiment of the present invention.

Figure 3 is a graph showing the pressure-resistance relationship of the pressure sensor in the embodiment of the present invention.

4 is a perspective view of a pressure sensing array in an embodiment of the present invention.

110. . . Protective film

120. . . Base

130. . . Spacer layer

200. . . Sensing range modulation structure

210. . . Upper control electrode

220. . . Nano carbon tube - liquid crystal composite layer

230. . . Lower control electrode

Claims (15)

A pressure sensor comprising: a sensing range modulation structure comprising a pinch structure consisting of an upper control electrode, a carbon nanotube-liquid crystal composite layer, and a lower control electrode, according to Electrically controlling the upper control electrode and the lower control electrode to adjust a direction angle of the carbon nanotube-liquid crystal composite material; a protective film layer covering the sensing range modulation structure and contacting the upper control electrode; a substrate disposed under the sensing range modulation structure to clamp the sensing range modulation structure between the protective film layer and the substrate, the substrate contacting the lower control electrode, wherein the lower control The electrical measurement result of the electrode is used for obtaining a pressure sensing value; and a spacer layer is interposed between the protective film layer and the substrate to space the sensing range modulation structure on the protective film The space between the layer and the substrate. The pressure sensor of claim 1, wherein the protective film layer is a conductive plastic film. The pressure sensor of claim 2, wherein the conductive plastic film is a polyester film. The pressure sensor of claim 1, wherein the spacer layer is made of a polymer material. The pressure sensor of claim 1, wherein the spacer layer is made of polydimethyl siloxane. The pressure sensor of claim 1, wherein the upper control electrode and the lower control electrode each have a thickness of 108 to 132 nm. The pressure sensor according to claim 1, wherein the thickness of the protective film layer is 90 to 110 μm, the thickness of the substrate is 630 to 770 μm, and the thickness of the spacer layer is 450~ 550 microns. The pressure sensor of claim 1, wherein the protective film layer has a thickness of 100 μm, the substrate has a thickness of 700 μm, and the spacer layer has a thickness of 500 μm. The thickness of the electrode and the lower control electrode are each 120 nm. A pressure sensing array comprising: a plurality of sensing range modulation structures, each of which comprises a pinch of an upper control electrode, a carbon nanotube-liquid crystal composite layer, and a lower control electrode a structure for adjusting a direction angle of the carbon nanotube-liquid crystal composite material according to electrical control of the upper control electrode and the lower control electrode; a protective film layer covering the sensing range modulation structure and contacting the Waiting for the control electrode; a substrate is located under the sensing range modulation structure to clamp the sensing range modulation structure between the protective film layer and the substrate, and the substrate is in contact with the lower control An electrode, wherein a pressure sensing result is obtained by an electrical measurement result of each lower control electrode; and a spacer layer is interposed between the protective film layer and the substrate to space the sense The measuring range modulation structure is a plurality of accommodating spaces between the protective film layer and the substrate. The pressure sensing array of claim 9, wherein the protective film layer is a conductive plastic film. The pressure sensing array of claim 10, wherein the conductive plastic film is a polyester film. The pressure sensing array of claim 9, wherein the spacer layer is made of a polymer material. The pressure sensing array of claim 9, wherein the spacer layer is made of polydimethyl siloxane. The pressure sensing array according to claim 9, wherein the protective film layer has a thickness of 90 to 110 μm, the thickness of the substrate is 630 to 770 μm, and the thickness of the spacer layer is 450~ At 550 microns, the thickness of each of the upper control electrode and each of the lower control electrodes is 108 to 132 nm. The pressure sensing array of claim 9, wherein the protective film layer has a thickness of 100 μm, the substrate has a thickness of 700 μm, and the spacer layer has a thickness of 500 μm, each of which The thickness of the upper control electrode and each of the lower control electrodes are each 120 nm.