Flexible Pressure Sensor Arrays with High Sensitivity and High Density Based on Spinous Microstructures for Carved Patterns Recognition

Owing to the superior stimulus perception, tactile function of skin is always the desire of flexible pressure sensor array (FPSA). However, achieving sensor arrays with high sensitivity and high resolution for tactile recognition like skin still remains a challenge. In this paper, an FPSA with high sensitivity (10.50 kPa-1), high density (1134.63 cm-2), and sufficient sensing units (4096 units) is developed, which is one of the best results up to now. The spinous microstructures, transferring from the abrasive papers, endow the sensor array with high sensitivity. Additionally, the high density array with adequate sensing units contributes to achieving high spatial resolution for identifying various surface features. This high-performance FPSA can obtain detailed pressure distribution for complex carved patterns. With the assistance of machine learning, the FPSA can realize precise tactile recognition, 98.48% accuracy for 12 types of mahjong tiles, indicating a promising potential in an intelligent recognition system. It is worth noting that the relationship between surface microstructures and consistency is systematically investigated for the first time, which offers valuable insights for the preparation of high-performance sensor arrays.