복합 재료의 형태 설계 및 임피던스 분석을 통한 변형 가능한 센서의 신호 분리

Abstract

Deformable sensor system is considered as the one of next generation hardware platform with the interest of real-time healthcare monitoring and robotic, prosthetics application. The sensor systems form intimate contact with target surface like human skin and collect various information from the environment. Various studies have been conducted to allow deformability in different form factor from conventional electronics. To establish reliable and practical deformable sensors, it needs to consider how the applied deformation changes the mechanical properties and electrical signals of material. Base on the information, the signal noises can be suppressed or calibrated. The impedance of material is determined by the types and the morphology of materials. I considered the absolute impedance values and its change in designing deformable sensor systems. In this work, the signal decoupling stands for 1) the elimination of strain influences in deformable electronics and 2) the crosstalk suppression in passive matrix tactile sensor. First, I designed composite materials using 0-dimensional (0D) and 1-dimensional (1D) nanomaterial. The 0-D and 1-D shaped nanomaterial were favorable to strain sensor and stretchable electrode respectively, based on percolation theory. The strain-sensitivity was controlled with morphology studies. The characteristics of elastomer matrix also affected the morphology of composite material. Second, I proposed the use of rectifier in passive matrix tactile sensor. The sneak current induces crosstalks between pixels and hampers the quality of signal. The designed interface presented the both strain sensitivity and rectification, so the signal of target pixel was able to be acquired without crosstalk using the simple structure. Third, I proposed the use of ion conductor as a multimodal sensor which is sensitive to strain and temperature. Each sensitivity was able to be decoupled through the impedance analysis of ion conductor and then measured in real-time. Calibration process using additional strain sensor was not required even under deformation. The concept using relaxation time can be a new platform in designing deformable sensor system.