Design, characterization and modeling of dielectric layer for all-fiber capacitive sensors

In order to prepare flexible all-fiber capacitors with good sensing and wearability, a sandwich fabric capacitive sensor was designed. The influence of the structure and thickness of the dielectric layer on the capacitance and sensitivity was analyzed. The results showed that different fabric weaves will affect the sensing performance by different thickness, mass per area and compression properties. Regardless of different fabric weaves, the permittivity and the fabric dielectric layer thickness have good linear relationship. Simultaneous changes in the distance between the two plates and the permittivity due to pressure is the sensing mechanism of fabric capacitive sensors. The formula of the capacitance change rate or sensitivity is given, which can be used to guide the development of the fiber-based capacitive sensor. Aramid's LO weave has a better performance,and has excellent stability, hysteresis and repeatability, which is expected to be used in human motion and physiological signal monitor.