Scalable Superior Chemical Sensing Performance of Stretchable Ionotronic Skin via a π‐Hole Receptor Effect

• DOI: 10.1002/adma.202007605
• Publication Date: 2021-02-20T16:51:25Z
• Authors: Ming Liang Jin; Sangsik Park; Hyukmin Kweon; Hyeong‐Jun Koh; Min Gao; Chao Tang; Soo‐Yeon Cho; Yunpyo Kim; Shuye Zhang; Xinlin Li; Kwanwoo Shin; Aiping Fu; Hee‐Tae Jung; Chi Won Ahn; Do Hwan Kim
• Keywords: Wearable Technology

Abstract Skin‐attachable gas sensors provide a next‐generation wearable platform for real‐time protection of human health by monitoring environmental and physiological chemicals. However, the creation skin‐like sensors, possessing high sensitivity, selectivity, stability, scalability (4S) simultaneously, has been big challenge. Here, an ionotronic gas‐sensing sticker (IGS) is demonstrated, implemented with free‐standing polymer electrolyte (ionic thermoplastic polyurethane, i‐TPU) as sensing channel inkjet‐printed stretchable carbon nanotube electrodes, which enables IGS to exhibit stability (against mechanical stress, humidity, temperature), scalable fabrication, simultaneously. The demonstrates reliable capability against nitrogen dioxide molecules under not only harsh stress (cyclic bending radius curvature 1 mm cyclic straining at 50%), but also conditions (thermal aging from −45 125 °C 1000 cycles humidity 24 h 85% relative humidity). Further, through systematic experiments theoretical calculations, π‐hole receptor mechanism proposed, can effectively elucidate origin sensitivity (up parts per billion level) selectivity system. Consequently, this work provides guideline design materials achievement high‐performance skin‐attachable gas‐sensor platforms.