Contact Modulated Ionic Transfer Doping in All‐Solid‐State Organic Electrochemical Transistor for Ultra‐High Sensitive Tactile Perception at Low Operating Voltage

• Published in: Advanced functional materials 2020-12, Vol.30 (51), p.n/a
• Main Authors: Chen, Shuai, Surendran, Abhijith, Wu, Xihu, Leong, Wei Lin
• Format: Article
• Language: English
• Subjects: conjugated polymer; Doping; Dynamic pressure; Electric potential; Electrolytes; Flexible components; flexible organic electronics; Ion transport; Ions; Materials science; Molten salt electrolytes; organic electrochemical transistor; Polymer films; Polymers; Pressure distribution; Pressure sensors; Robotics; Semiconductor devices; Sensor arrays; solid electrolyte; Solid electrolytes; Stress concentration; Tactile discrimination; Transconductance; Transistors; ultrasensitive pressure sensor; Voltage
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202006186

Ionic‐electronic coupling across the entire volume of conjugated polymer films endows organic electrochemical transistors (OECTs) with high transconductance (gm) and low operating voltage. However, OECTs utilize liquid electrolytes, which limit their long‐term operation, reproducibility, and integration while solid electrolytes typically result in inefficient ion transport. Here, a solid polymer electrolyte is shown that can facilitate good electrochemical response in conjugated polymers and yield high OECT performance. This allows for the OECT‐based pressure sensors, modulated through a pressure sensitive ionic doping process. The pressure sensor exhibits the highest sensitivity ever measured (≈10 000 kPa−1) and excellent stability. Flexible sensor arrays achieve static capture of spatial pressure distribution and enable monitoring of dynamic pressure stimuli. The findings here demonstrate that all‐solid‐state OECTs are good candidates for providing rich tactile information, enabling applications for soft robotics, health monitoring, and human‐machine interfaces. High performance all‐solid‐state organic electrochemical transistors (OECTs) are developed. With the use of novel contact modulated ionic doping mechanism, these all‐solid‐state OECTs are also demonstrated to be good candidates for providing tactile information, presenting tunable pressure sensitivity, low operating voltage, and excellent stability over time. Flexible sensors arrays demonstrate the ability to map pressure distribution and track motion.