Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Jonathan Seppala (Fed)

Chemical Engineer

Jonathan Seppala is currently the technical lead in the additive manufacturing effort in the Polymer Processing and Rheology Project. His current research focuses on using infrared thermography, rheology, fracture mechanics, and neutron and x-ray reflectivity to study the polymer physics of thermoplastic additive manufacturing processes. Jonathan earned a B.S. in Chemical Engineering from Michigan Technological University and a Ph.D. in Chemical Engineering from Michigan State University studying the rheology and thermodynamics of polymer nanocomposites. Following his Ph.D., Jonathan worked as a Postdoctoral Researcher studying thin film self-assembly of block copolymers and equilibrium dynamics of amphiphilic micelles at the University of Delaware. Prior to joining the Polymer Processing and Rheology project, Jonathan studied ballistic witness materials and shear thickening fluids as part of the Personal Body Armor Project at NIST. 


Book front cover, Polymer-Based Additive Manufacturing: Recent Developments, with yellow 3D printed object

This book was inspired by the 2017 ACS Symposium “Additive Manufacturing of Structures and Functional Devices: Materials, Methods, Models, and Testing” and is supplemented by additional experts in the polymer AM field. The chapters discuss the technologies, measurement challenges, manufacturing opportunities, and fabrication potentials. We begin with an introduction to polymer additive manufacturing, identifying the measurement needs and technical challenges facing the industry. A chapter reviewing polymer powder bed fusion follows, providing a complete discussion on methods, materials, and applications. The bulk of the book covers thermoplastic material extrusion, with chapters discussing recycling-based feedstocks, composites materials, and multi-physics modeling linking experimentation and theory. Moving from thermoplastics to conductive inks, a chapter on in situ monitoring and control of direct-ink-write provides a clear example of how theory and modern machine vision can be used to create a practical and responsive control system. The last chapter provides a state-of-the-art review of multi-photon printing, discussing methods, materials, and the stunning capabilities of the technique.

Polymer-Based Additive Manufacturing: Recent Developments


Adhesion Society Distinguished Paper Award (2017)


Created May 31, 2018, Updated June 15, 2021