Paper-Based Electret Sensor/Actuator Array for Tactile Interaction

Abstract

This study proposes a portable, paper-based tactile feedback system interaction device, engineered to serve blind users with an integrated platform for both input and output functionalities. The device comprises six functional units, each measuring 10 × 10 mm, crafted using a sandwiched structure of paper substrate, graphite, and two PLA films via the hot-pressing technique. Utilizing the corona charging method, the PLA electret films exhibit an impressive piezoelectric coefficient peaking at 3578 pC/N, making it highly sensitive for both sensing and actuating. The pressure sensor, used for writing purposes, demonstrates a sensitivity of 1.01 V/N, while the vibration actuator, used for reading, achieves an output force of 60 mN at an applied voltage of 400 V. Notably, both the surface charge density and the performance of the sensor and actuator stabilize post approximately 1000 interactions. Our psychophysical experiments indicate the device has a perceptible threshold voltage as low as 50 V. Subsequent tactile interaction communication tests offer a preliminary validation of the device’s applicability. The proposed tactile interaction device, being flexibly constructed and intrinsically biodegradable, paves the way for cost-effective tactile communication solutions.