4-Dimensional Sensing in Interactive Displays Enabled by Both Capacitive and Piezoelectric Based Touch Panel

• Main Authors: Shuo Gao, Yanpei Shi, Qiang Liu, Lijun Xu, Bo Fu, Zongyin Yang
• Format: Article
• Language: English
• Published: IEEE 2019-01-01
• Series: IEEE Access
• Subjects: Interactive display; piezoelectric material; force sensing and hover touch sensing
• Online Access: https://ieeexplore.ieee.org/document/8664155/

Interactive displays have been intensively used in consumer electronics, e.g., smartphones, for providing highly efficient human-machine interactions, assisting users to process a vast amount of data. However, current mainstream interactive displays only support 2-dimensional detection, strongly limiting user experience. In this paper, we present a piezoelectric and capacitive based technique for obtaining 4-dimensional detection, including (x-y axis) location, force, and hovers sensing in interactive displays. Here, electrodes are located on and underneath the piezoelectric layer, constructing a sandwich structured device. A self-capacitance-based technique is employed for location and hover sensing. Force-induced charges are collected and interpreted as force amplitude. As capacitive and piezoelectric sensing techniques occupy different frequency bands, these two signals can be smoothly separated, and 4-dimensional touch sensing is achieved concurrently, with the recognition of static force and hovers touch events.