Printable Stretchable Silver Ink and Application to Printed RFID Tags for Wearable Electronics.

Tao Zhong,Ning Jin,Wei Yuan,Weibing Gu,Chunshan Zhou,Zheng Cui

doi:10.3390/ma12183036

Abstract

A printable elastic silver ink has been developed, which was made of silver flakes, dispersant, and a fluorine rubber and could be sintered at a low temperature. The printed elastic conductors showed low resistivity at 21 μΩ·cm, which is about 13.2 times of bulk silver (1.59 μΩ·cm). Their mechanical properties were investigated by bending, stretching, and cyclic endurance tests. It was found that upon stretching the resistance of printed conductors increased due to deformation and small cracks appeared in the conductor, but was almost reversible when the strain was removed, and the recovery of conductivity was found to be time dependent. Radio-frequency identification (RFID) tags were fabricated by screen printing the stretchable silver ink on a stretchable fabric (lycra). High performance of tag was maintained even with 1000 cycles of stretching. As a practical example of wearable electronics, an RFID tag was printed directly onto a T-shirt, which demonstrated its normal working order in a wearing state.

Highlights

The development of wearable electronics are thriving due to many potential applications such as electronic skins [1], flexible and stretchable displays [2], personal health monitoring [3], human motion capturing [4], and smart textiles [5], etc
Passive radio-frequency identification (RFID) tags equipped with stretchable antennas have been found to be an ideal approach because they can be powered by harvesting ambient energy
Two commercial silver inks, which were made of silver nanoparticles and silver flakes respectively, were compared with the elastic conductive ink

Summary

Introduction

The development of wearable electronics are thriving due to many potential applications such as electronic skins [1], flexible and stretchable displays [2], personal health monitoring [3], human motion capturing [4], and smart textiles [5], etc. As the human body is soft, elastic, and curved, the wearable devices should withstand various strains while still maintain their normal performance under these deformations [7]. How to fabricate such stretchable electronic systems becomes a critical technical issue [8]. Many wearable systems should have the functions of wireless communication for data transfer and are desirable to be battery-free to achieve light weight [9,10].

Methods

Results

Conclusion