Eco-friendly screen printing of silver nanowires for flexible and stretchable electronics

Screen printing is a promising route towards high throughput printed electronics. Currently, the preparation of nanomaterial based conductive inks involves complex formulations with often toxic surfactants in the ink's composition, making them unsuitable as an eco-friendly printing technology. This work reports the development of a silver nanowire (AgNW) ink with a relatively low conductive particle loading of 7 wt%. The AgNW ink involves simple formulation and comprises a biodegradable binder and a green solvent with no toxic surfactants in the ink formulation, making it an eco-friendly printing process. The formulated ink is suitable for printing on a diverse range of substrates such as polydimethylsiloxane (PDMS), polyethylene terephthalate (PET), polyimide (PI) tape, glass, and textiles. By tailoring the rheological behaviour of the ink and developing a one-step post-printing process, a minimum feature size of 50 mu m and conductivity as high as 6.70 x 10(6) S m(-1) was achieved. Use of a lower annealing temperature of 150 degrees C makes the process suitable for plastic substrates. A flexible textile heater and a wearable hydration sensor were fabricated using the reported AgNW ink to demonstrate its potential for wearable electronic applications.

Automated summary

This study reports a silver nanowire ink with low conductive particle loading and an eco-friendly printing process suitable for printing on different substrates. The ink has simple formulation using biodegradable binder and non-toxic solvent, achieving a minimum feature size of 50 μm and a high conductivity of 6.70 x 10^6 S m^(-1). Flexible textile heater and wearable hydration sensor were fabricated to demonstrate the potential for wearable electronic applications.