Research On The Flexible Wearable Integrated Sensor Technology

Flexible wearable electronics are loved by people because of their thinness,portability and high integration.To simulate human tactile,the researchers integrated tactile sensor with flexible electronics and proposed a wearable tactile sensor that can be attached to human skin directly.When designing a wearable tactile sensing system,it needs not only to achieve device flexibility but also peripheral circuit flexibility in order to make the flexible tactile sensor highly integrated with the peripheral circuit.In addition,the wearing comfort of the wearable system should also be considered.This article mainly studies tactile sensing and its wearable integrated technology.The main research contents of this article include:(1)The sensitivity error of a three-axis tactile sensor with a tactile boss is analyzed.The effect of applying shear force on the sensitivity of the sensor at different locations on the sidewall of the haptic boss was analyzed by the finite element method.The result shows that the closer the side wall of the tactile projection is to the upper electrode layer membrane,the lower sensitivity of the sensor in the shear direction is.In addition,the sensor error is analyzed,which is caused by the deviation of the shape of the tactile hub structure due to the process error.The result shows that the larger the deviation angle of the structure of the tactile boss structure will reduce the sensitivity of the principalaxis and increase the cross-axis coupling.(2)A high-sensitivity capacitive flexible tactile sensing array is designed.A middle isolation layer structure with an open trench structure is proposed.A sensor with an open trench structure can effectively improve the sensitivity of the sensor.The feasibility of the proposed structure was verified by simulation.The results show that,under the same pressure,the change of the sensor capacitance distance of the open trench structure is 10 times that of the non-open trench structure,which increases the capacitance change and improves the sensitivity of the sensor.After simulation and matlab calculation,the sensitivity of the sensor is 18.97%/m N,and the nonlinearity is 2%.(3)Based on the skin comfort,the size of the VIAs in the multilayer extensible flexible circuit and the connection angle between the serpentine interconnects and the VIAs were studied.The results show that the VIA's radius is within 400?m,which meets the comfort requirements of most skin locations(skin strain within 15%);When the connection angle of the erpentine interconnects and the VIA is an acute angle,it will reduce the comfort on the skin below the VIA.When the connection angle is between 120 ° and 180 °,the skin comfort can be improved.(4)The effect of the layout of VIAs in multilayer extensible flexible circuit on skin comfort was analyzed.By comparing the skin comfort of the concentrated VIA layout and dispersed VIA layout,it is found that the concentrated VIA layout can reduce the mechanical constraints on the skin of the extensible flexible system.In addition,replacing the flexible substrate that is close to the skin with Silbione with a lower Young's modulus can effectively enhance skin comfort.