Highly Sensitive Silver-Microlayer Thin Film on a pp-PFM-Modified PDMS Strain Sensor as a Versatile Tool for Stretchable Electronics Applications

Abstract

Strain sensors for wearable electronic devices have received attention due to their potential application in medicine for physiological monitoring or as part of advanced prosthetics. However, low sensitivity values as well as complex fabrication procedures remain significant challenges limiting the applicability. This work presents the fabrication of a strain sensor based on the separation of silver microplates immobilized on a stretchable substrate. The deposition of the microplates is achieved through the exposition of a glucosamine-functionalized surface to the Tollens’ reagent, being a versatile fabrication methodology able to be implemented in a wide range of substrates. The obtained sensors present a high stretchability (>100%), high conductivity (105 S m–1), good linearity (R2 > 0.98 under 30% strain), good hysteresis properties, and high sensitivity (up to GF = 900 000). Hence, the sensors allow the measurement of very small deformations even in dynamic range, where it presents a stable linear response for the quantification of cyclic deformations of 0.02% strain. Moreover, the applicability of these sensors has been studied in motion-sensing devices and in a pressure sensor revealing that this technology may expand the potential applications of wearable electronic devices.