[0029] Example 1
[0030] A light-assisted method for enhancing the sensitivity of stress sensors, such as Figure 5 , 6 As shown, the light-assisted method is adopted: the stress sensor based on the two-dimensional material is subjected to light while the electrical properties are changed under the influence of stress; the light is used as an auxiliary effect to inject additional carriers into the two-dimensional material, so that the electrical properties of the two-dimensional material are changed. The amplitude increases, so as to achieve the purpose of improving the sensitivity of the stress sensor.
[0031] The high-sensitivity stress sensor prepared by the above method includes: a two-dimensional material, a flexible substrate, a conductive electrode, a wire and a light source; the two-dimensional material is placed on the flexible substrate, and the conductive electrode is placed on the two-dimensional material and the flexible substrate. between the substrates; illuminate the two-dimensional material part with a light source; connect wires on the conductive electrodes, so that the entire sensor can be easily connected to the electronic system.
[0032] The working method of the high-sensitivity stress sensor is as follows:
[0033] as attached figure 1 As shown in the operation step 1, a piece of 2D material is transferred to a piece of flexible substrate, here for example SnS 2 The material is transferred to the PDMS substrate.
[0034] as attached figure 2 As shown in the operation step 2, a mask is made on the two-dimensional material. First, a suitable mask is formed by ultraviolet photolithography, and then a layer of Ti metal is plated on one side of the mask by vacuum evaporation. and a layer of Au metal, and then use acetone alcohol to remove the mask to form the required conductive electrodes. For the sake of simplicity, only 2-terminal electrodes are shown in the figure, and more complex electrode structures can also be used.
[0035] as attached image 3 As shown in the operation step 3, the stress sensor is connected into the electronic system with wires to facilitate the use of the device, and the optical auxiliary sensor is connected with a wire to a meter that can apply a specific bias voltage and read the flowing current.
[0036] as attached Figure 4 As shown in the operation step 4, the light source is used to provide auxiliary illumination to the two-dimensional material part, and photogenerated carriers are injected to change the electrical properties of the material itself, improve the stress sensitivity, and prepare for stress sensing. With 400nm wavelength, 10mW/cm 2 The energy density of light, illumination SnS 2 material part, so that the current flowing through the material is greatly increased.
[0037] as attached Figure 7 As shown in the 5 basic deformation modes of the light-assisted stress sensor, all 5 forms will bring stress to the stress sensor. The left side is a simple side view of the light-assisted stress sensor, only the larger part of the flexible substrate is drawn, and the two-dimensional material is above the flexible substrate by default. The deformation method on the right side from top to bottom is described in the text in the figure.
[0038] as attached Figure 8As shown in the simple description of the principle of light-assisted improving the sensitivity of the stress sensor, when a certain bias voltage is applied to the two poles of the two-dimensional material, the current flowing through the two-dimensional material is at a moderate level, and when subjected to stress, the current will decrease to a low level, which is the basic principle of traditional stress sensors; when the 2D material is assisted by light, the initial current of the 2D material itself will increase to a higher level, and when subjected to stress, The current will drop to a lower level. Because the light-assisted method has more relationship between the light-injected carriers and the stress effect than the realization principle of the traditional stress sensor, the light-assisted method is used to additionally superimpose the response of the light effect to the stress, which can improve the performance of the stress sensor. sensitivity.
[0039] as attached Figure 9 As shown in the test material is SnS 2 , Figure A is the current change curve of the sample under dark conditions, the deformation increases from 0 to 3.123% with time, according to the calculation, the sensitivity of this sample is only 20.6 in the dark state; Figure B is the sample under light conditions. , the current change curve of the deformation increasing from 0 to 2.031% with time, according to the calculation, the sensitivity of this sample can reach 960.1 in the light state; Figure C is a comparison of the SnS 2 The difference between the sensitivity GF of the sample in the dark and the light shows that the light amplifies the sensitivity by 48 times.
