Aining at the problem that measurement range of flexible sensor for bending angle measurement of finger joint is limited and linearity is not high

a transparent sensor based on ionic skin is prepared for measuring finger joint bending angle with wide range and high linearity. The sensor is made up of silicon rubber thin film and highly stretchable ionic conductors containing lithium chloride. Angle sensing theoretical model for sensor is proposed

which tests the relationship between bending angle of finger joint and capacitance signal of sensor. The experimental result shows that the sensor has the characteristics of better linearity and wider measuring range

compared to other flexible sensors. It can measure the angle of finger joints over the whole movement range with a linearity of 4. 84 %. In addition

the sensor has simple preparation process and low price

and has good application prospects in the fields of rehabilitation engineering and robotics.