05/03/2023
By Kailey Miller

The Francis College of Engineering, Department of Mechanical Engineering, invites you to attend a Master’s thesis defense by Kailey Miller on “Experimental and Numerical Characterization of Stretchable Conductor Traces with Straight and Curved Geometries.”

Candidate Name: Kailey Miller
Degree: Master of Science in Engineering
Defense Date: Thursday, May 11, 2023
Time: 2 to 4 p.m. EST
Location: Alumni Hall 103
There will be a virtual defense via Zoom for those unable to attend in person. Those interested in attending should contact the student (Kailey_Miller@student.uml.edu) and committee advisor (Alireza_Amirkhizi@uml.edu) at least 24 hours prior to the defense to request access to the meeting.
[This information is for internal use only and will not be posted as part of the Announcement.]

Committee

  • Advisor Alireza Amirkhizi, Ph.D., Mechanical Engineering, University of Massachusetts Lowell
  • Joey Mead, Ph.D., Mechanical Engineering, University of Massachusetts Lowell
  • Scott Stapleton, Ph.D., Mechanical Engineering, University of Massachusetts Lowell

Abstract:
Compared to traditional conductors used in flexible structures, intrinsically stretchable conductors allow for a greater variety of applications due to superior potential integration with biological materials and textiles. Screen printing is a low cost and adaptable method for depositing conductive inks and protective encapsulants on stretchable substrates such as thermoplastic polyurethane (TPU). Viscoelastic deformation response of bare substrates as well as double encapsulated conductive traces printed using a screen-printing process were recorded under stretch to failure (200% strain) and cyclic loading (10% strain). Local deformation patterns were also determined using digital image correlation (DIC). Finite element models of straight and serpentine patterned interconnects were generated in HyperMesh and calibrated in Abaqus CAE to match experimental results from dynamic and quasi-static testing of bare substrate and of double encapsulated conductive traces. A robust model allows for simulation of the unique stress response characteristics and stretchability of patterned geometry as well as common modes of failure. These simulations and experiments improve understanding of stretchable conductors and encapsulants and will lead to appropriate design choices for flexible electronics using such conductors in contrast with designs using traditional conductor traces.