Highly transparent and flexible Ag nanowire-embedded silk fibroin electrodes for biocompatible flexible and transparent heater.

Jin-Hyeok Park,Sanghyuk Park,Eswaran Kamaraj,Hae-Jun Seok,Han-Ki Kim

doi:10.1039/d0ra05990k

Jin-Hyeok Park, Sanghyuk Park + Show 3 more

Open Access

https://doi.org/10.1039/d0ra05990k

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Abstract

We investigated the electrical, optical and mechanical properties of silver (Ag) nanowire (NW) embedded into a silk fibroin (SF) substrate to create high performance, flexible, transparent, biocompatible, and biodegradable heaters for use in wearable electronics. The Ag NW-embedded SF showed a low sheet resistance of 15 Ω sq−1, high optical transmittance of 85.1%, and a small inner/outer critical bending radius of 1 mm. In addition, the Ag NW-embedded SF showed a constant resistance change during repeated bending, folding, and rolling because the connectivity of the Ag NW embedded into the SF substrate was well maintained. Furthermore, the biocompatible and biodegradable Ag NW-embedded SF substrate served as a flexible interconnector for wearable electronics. The high performance of the transparent and flexible heater demonstrated that an Ag NW-embedded SF-based heater can act as a biocompatible and biodegradable substrate for wearable heaters for the human body.

Highlights

We investigated the electrical, optical and mechanical properties of silver (Ag) nanowire (NW) embedded into a silk fibroin (SF) substrate to create high performance, flexible, transparent, biocompatible, and biodegradable heaters for use in wearable electronics
By employing the Ag NWembedded SF substrate to fabricate exible interconnectors and TFHs, we demonstrate the feasibility of biocompatible Ag NW-embedded SF substrates for wearable electronics and the possibility that they can be substituted for conventional highcost ITO lms
The optical transmittance of the Ag NW-embedded SF substrate was compared with Ag NWs/ poly-ethylene terephthalate (PET) at wavelengths from 350 nm to 1200 nm using a UV/Vis spectrophotometer (V-670, Jasco)

Summary

Introduction

Electrodes.[40] Min et al demonstrated that patterned Ag NW on a SF substrate acts as a transparent resistor and a radiofrequency antenna for food sensors.[41] Qi et al reported that Ag NW and SF composite lms have excellent transmittance and conductivity and can be used as exible interconnectors. Several applications of Ag NW–SF compositions or Ag NW-coated SF substrates, such as bacteria sensors, photonics, electronic devices, food sensors, actuators, therapeutics, and energy harvesting devices have been suggested, their use as electrodes for wearable transparent and exible heaters (TFHs) has not yet been reported. By employing the Ag NWembedded SF substrate to fabricate exible interconnectors and TFHs, we demonstrate the feasibility of biocompatible Ag NW-embedded SF substrates for wearable electronics and the possibility that they can be substituted for conventional highcost ITO lms

Experimental

Fabrication and evaluation of the thin- lm heaters

Results and discussion

Conclusions