The innovation engine for new materials

Terrence Polk

Terrence Polk




University of Houston


Leanne Friedrich

Faculty Sponsor(s): 

Matthew Begley

Faculty Sponsor's Department(s): 


Project Title: 

Conductivity in 3D Printing Ink using Acoustically Focused Microparticles

Project Description: 

3D printing is a growing field of engineering and design with its ability to produce products made entirely in one piece that are much lighter than multicomponent parts made of similar materials while still being strong and rigid. The ability to print conductive inks using acoustically focused particles will allow us to print multifunctional components that can be made conductive or non-conductive by toggling focusing. Acoustical focusing is achieved by using a piezoelectric device and signal generator to create a standing wave inside our printing channel1. When the particles flow through the channel, the standing wave pushes the particles towards the center creating a line of particles in the ink.  We tested various concentrations of silver coated copper spheres and dendrites inside an epoxy base insulator to see trends in conductivity.  We found a formula that had good conductivity and took it to our linear printing stage to print lines and retest the conductivity. The linear printing stage utilizes a linear stage, a mass flow controller, two cameras, and a Matlab script to control it all. We found that 20% spheres, 40% dendrites and 40% epoxy base exhibited the best conductivity with a resistivity of .0011Ωm; however, this concentration is not printable as that concentration of dendrites will clog the tubing. We took this information and scaled down the concentration of spheres and dendrites using the 1:2.02 ratio from the 20%/40% ink to achieve similar conductivity in a printable concentration by forcing less the particles into close proximity.