(729j) Layered Polymer/Particle Composites for Electronic and Sensing Applications

Polymers display high flexibility and nanoparticles can introduce desirable electrical or thermal properties. We will demonstrate the use of polymers and nanoparticles in layered composites to enable mechanically durable and functionally versatile composites. Traditional manufacturing using extrusion or injection can make composites quickly, but the limitation is the resolution control (e.g., tens of microns or even worse). The optimization of composite microstructures involves tooling engineering that can be costly and time-consuming. This research will demonstrate the use of rapid prototyping, also known as 3D printing, with high compatibility to nanomaterial assembly methods to manipulate the layer distribution of polymers and particles so that well-designed patterns can be quickly formed. We used chopped carbon fibers or discrete carbon nanotubes to demonstrate the layered structures and the manufacturability with different material systems. These carbon materials' layers incorporated among polymer channels demonstrated directional properties in electrical conductivity, showing high potential in sensor applications responsive to low-concentration volatile gases, strain, and pressure stimuli. The mechanical robustness of these materials was also characterized using impact and scratch tests, demonstrating the using longevity of these devices. The reported manufacturing combining 3D printing and particle assembly shed light on rapidly prototyped devices and demonstrated their broad applications in sensors, actuators, soft robotics, and medical scaffolds.