Highly linear capacitive tactile sensor with elastic dome-shaped electrodes

Abstract

Capacitive tactile sensors have been widely used for electronic skins and human-machine interfaces due to their high sensitivity, low power consumption, and fast response. Despite great advances in improving the sensitivity of the sensors through structural design or advanced material selection, achieving linear response over a broad detection range for pressure sensing is still a great challenge. Herein, a capacitive tactile sensor with elastic dome-shaped electrode is reported. We find that the elastic dome-shaped electrode can significantly enhance the linear relationship between the effective electrode area of the capacitor and the applied force over a wide range, which endowed the prepared sensor exhibiting excellent linearity (R 2 = 0.999) up to 120 kPa. In addition, the fabricated sensor sample has good stability, quick response, satisfied sensitivity of 0.115 kPa−1 (0–120 kPa), and can be further expanded with a wider sensing range up to 500 kPa. Based on the proposed model, the sensitivity and linear sensing range of the sensor can be designed flexibly for different application. It can provide a simple but powerful strategy to construct high performance flexible pressure sensors in the future.