Fabricating of double layered flexible pressure sensor with a high-sensitivity based on inkjet printed micro-concave structure

With a good mechanical flexibility and excellent sensing performance, flexible pressure sensor is widely used in electronic skin, motion detection, biomedicine, wearable devices and other fields. Micro-structured surface and electrode structure are the key factors for realizing a high-sensitivity of flexible pressure sensor. Inkjet printing has the characteristics of high production efficiency, good compatibility and accurate deposition on various substrates. In this article, micro-concave surface is generated as a template by inkjet printing technology, then a micro-convex PDMS surface is prepared by a facile replica technique, which could be used as a flexible pressure sensor through air phase depositing silver. Mechanical and electrical properties of the micro-convex flexible electrode are optimized by exploring the thickness of PDMS layer and silver layer. Then two micro-convex flexible electrodes are assembled as a double layered flexible pressure sensor by a face-to-face stacking, which could present a high sensitivity compared to single micro-convex flexible electrode. This study provides a facile method for the preparation and application of high-sensitive flexible pressure sensor.