Paper-based electronics are emerging as lightweight, recyclable, and low-cost options for advanced mechanical, chemical, and electrical sensing. As one potential application of paper-based electronics, skin-like sensors may be capable of detecting touch, temperature, pressure, and humidity on synthetic or natural surfaces. Current efforts to fabricate paper-based electronic devices – papertronics – include printing, coating, and laser processing of off-the-shelf paper.
In this presentation, we describe a method for manufacturing tunable electronic composites for skin-like sensors. We apply papermaking techniques to produce highly porous composites of cellulose fiber loaded with carbon black. Detailed characterization shows their conductive performance across a range of frequencies. These composites also have a nonlinear, percolating increase in conductivity with respect to their concentration of carbon black.
For elastic deformation, our composites show piezoresistive behavior with electrical resistivity dependent on applied pressures or forces. Testing of mechanical strength also shows the effect of the embedded nanoparticles on cellulose-based composites. Furthermore, we embossed the composite paper to tune its porosity and thus enhance its conductivity. Overall, this work demonstrates a simple and scalable method to fabricate composites with tunable electromechanical properties for paper-based skin sensors. Our approach has the potential to open opportunities for prosthetics and robotics, haptic feedback, and structural health monitoring on expansive surfaces of buildings and vehicles.