Direct 3D Printing of Graphene Nanoplatelet/Silver Nanoparticle-Based Nanocomposites for Multiaxial Piezoresistive Sensor Applications

As a new area of biological integration systems ranging from fitness to costume, arable electronic devices are extensively investigated and recently focused on the development of customized and highly interactive devices with human-friendly factors. Here, a facile method of integrating a three-dimensional printing (3DP) with stretchable and conductive nanocomposite materials to form a multiaxial piezoresistive sensor that can detect human motion is presented. The multiaxial piezoresistive sensors are fabricated through direct 3DP of nanocomposites based on graphene nanoplatelets (GNPs), silver nanoparticles (AgNPs), and polyurethane. The sensor can detect not only compression, but also tensile strain upto more than 160%. Based on the synergy between GNPs and AgNPs, the sensor shows high sensitivity with a gauge factor of 48.2, which is a much higher value considering that most of the previously reported stretchable strain sensors are less than 35. In addition to the high sensitivity, the GNPs/AgNPs nanocomposite sensor exhibits a fast response time and excellent stability over 500 cycles. When the sensor is integrated into an LED light system, it functions as an interactive device that can control the intensity of light by detecting various human motions such as the bending of fingers.