Fabrication of ZnSnO3 based humidity sensor onto arbitrary substrates by micro-Nano scale transfer printing

• Published in: Sensors and actuators. A. Physical. Vol. 246; pp. 1 - 8
• Main Authors: Aziz, Shahid, Bum, Kim Go, Yang, Young Jin, Yang, Bong-Su, Kang, Chul Ung, Doh, Yang Hoi, Choi, Kyung Hyun, Kim, Hyung Chan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2016
• Subjects: Flexible humidity sensor; PDMS; Transfer printing; WSS; ZnSnO3; ZnSnO3; Flexible humidity sensor; WSS; Transfer printing; PDMS
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2016.04.059

•The paper discusses a very low cost and simple technique for transferring printed electronic devices from flat substrates to any arbitrary curved substrates including exoskeleton of sea crab and ultra-light weight substrate like the wing of a dragon fly.•We hope that this research will contribute to the betterment of environment, economic and research and development in the scientific community. A flexible humidity sensor has been fabricated by a transfer printing technique. The device is fabricated by spin coating a composite of an equal (1:1) wt% ink of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and zinc-stannate (ZnSnO3) on a water soluble substrate (WSS), screen printing silver interdigitated (IDT) electrodes and spin coating low modulus Polydimethylsiloxane (PDMS) on top of the IDTs. The water soluble substrate is then dissolved and removed and the device is laminated onto an arbitrary substrate in an inverted configuration. The device performance has been tested by transferring onto curved plastic substrates with different radii of curvature Rc. The devices show impedance change from ∼18MΩ to ∼1.8MΩ from 0% to 90% relative humidity (RH) with a negligible variation in results, over different bending radii. The transfer printing technique reported here would provide efficient and reliable route for the fabrication of flexible electronics on nonconventional substrates in environmental sensing, soft robotics, and artificial skin etc.