(734g) Hybrid 3D Printing for Advanced Sensors

This report will include investigations of new hybrid manufacturing for advanced sensor devices. We will first use CLIP method for surface patterning on which inks of super low viscosity was written. The surface patterning will generate microchannels of controlled dimensions, and here microchannels of 100 um*100um sizes were used. A simple droplet on desirable locations will drive the inks into the microchannels for uniform dispersion. The nanoparticle-containing inks then deposited following drying thermodynamics-controlled sedimentation. The directed assembly is controlled by microforces, such as gravity, viscous drag, van der Waals, capillarity, and hydrogen bonding. A control of the nanoparticle size would also facilitate the trapping of particles with long-range orders. The eventually formed structures showed one-dimensional nanoparticle alignment at nanoscale, two-dimensional stacking layers at microscale, and continuity along surface patterns at macroscale. These hierarchical structures showed enormous potential in anisotropic conductivity and sensing capabilities, demonstrated in our case studies for finger bending, wrist rotation, and general bending tests.