Interference-free nanogap pressure sensor array with high spatial resolution for wireless human-machine interfaces applications

Abstract

Pressure sensors provide intuitive and easy-to-use information, making them essential for Human-Machine Interface (HMI) applications. However, capacitive pressure sensors, although prevalent in industrial applications, suffer from critical vulnerabilities to external interferences like water droplets and proximity. Without addressing these issues, pressure sensors can never be effectively utilized in various real-world applications. This paper addresses this critical issue by identifying fringe fields as the primary cause of interference and proposing a nanogap structured capacitive pressure sensor. By reducing the electrode gaps to hundreds of nanometers, our sensor effectively mitigates fringe field effects, ensuring reliable pressure detection and high spatial resolution. We demonstrate the sensor’s capabilities through wireless applications such as an artificial pressure sensing system and a force touch pad system, both showcasing exceptional resilience and accuracy. This innovation paves the way for robust, interference-free pressure sensors, significantly advancing HMI technology. The authors use a nanogap structure in capacitive pressure sensors to suppress fringe fields, the cause of interference. This enables interference-free operation while achieving high resolution and bending insensitivity for human-machine interface applications.