06/03/2025
By Danielle Fretwell

The Francis College of Engineering, Department of Chemical Engineering, invites you to attend a Master's Thesis defense by Andrew Chapman on: "Exploration and Application of Tin-Indium Nanoparticles for Processing and Printing E-textiles."

Candidate Name: Andrew Chapman
Degree: Master’s
Defense Date: Friday, June 13, 2025
Time: 2 to 4 p.m.
Location: Perry 415

Committee:
Advisor: Zhiyong Gu, Department Chair (Professor), Chemical Engineering, University of Massachusetts Lowell

Committee Members

  • Nese Orbey, Associate Chair for UnderGrad (Associate Professor), Chemical Engineering, UMass Lowell
  • Stephen Lam, Director of Nuclear Engineering (Assistant Professor),Chemical Engineering, UMass Lowell
  • Edward Fratto, Postdoctoral Researcher, DEVCOM U.S. Army Natick Soldier Systems Center

Abstract:
This research explored the applications of Tin-Indium (Sn-In) nanoparticles in E-textiles. The SnIn nanoparticles were successfully synthesized with an average diameter of 100nm and an alloy composition of indium that ranged from 53%-60% per batch. The melted samples are visually, elementally, and electrically compared to the un-melted samples to explore any differences or benefits the low melting point Sn-In nanoparticles have for E-textile applications. Industry standards were used to create a typical reflow profile that could be used to solder or melt the particles on the surface of the fabric. An experimental analysis of the crafted industry reflow profile was conducted to acquire the desired melting morphology and ensure efficiency. The analysis tested the time and temperature of the soak period or preheat stage of the particle, as well as the temperature and time of the peak zone, or when the particles are actively melting and soldering to components or surfaces. It was found when conducted at atmospheric conditions, a reflow profile with a soak period of 2 minutes at 100°C , and a reflow peak of 150°C that can range from 30seconds to 2mins would create the desired melting morphology.

With a low melting point temperature, below 130°C, the synthesized nanoparticles that are printed on the fabric can be melted directly on to the surface of fabric. With an established reflow profile and in the presence of vapor flux the particles could be melted at low temperatures into a visually coherent film. Conductivity of the film was lost slightly but still retained after melting, and enhanced by the presence of additional printed materials like Tin nanoparticles. To further test the application of the printed and low melting point nanoparticles prints in E-textiles, joints from the printed surface to a copper wire were attempted with a low melting point solder. A successful joint was created with composite material prints; however, the processing method was found to be different than that of most electronic industry standards. Due to the porous nature of cotton and the liquidation of solder paste when melted, the industry standard of pre-dispensing the solder paste did not work well to form joints. Instead, the printed layer must be heated up to the melting point of the solder paste, and then the solder paste is dispensed slowly and precisely to create the joint.