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Jonathan Seppala (Fed)

Chemical Engineer

Jonathan Seppala leads the Polymer Additive Manufacturing and Rheology Project, developing multi-modal and in situ measurements that enable control over the complex non-equilibrium material dynamics that characterize soft matter processing. His current research uses infrared thermography, rheology, polarized light, fracture mechanics, and neutron and x-ray reflectivity and scattering 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. Before joining the Additive Manufacturing and Rheology Project, Jonathan studied ballistic witness materials and shear thickening fluids as part of NIST's Personal Body Armor Project.


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


William P. Slichter Award (2021)

Adhesion Society Distinguished Paper Award (2017)

Selected Publications

Weld formation during material extrusion additive manufacturing

Jonathan E. Seppala, Seung Hoon Han, Kaitlyn E. Hillgartner, Chelsea S. Davis, Kalman D. Migler
Material extrusion (ME) is a layer-by-layer additive manufacturing process that is now used in personal and commercial production where prototyping and


Suppression of filament defects in embedded 3D printing

Leanne Friedrich, Ross Gunther, Jonathan Seppala
Embedded 3D printing enables the manufacture of soft, intricate structures. In the technique, a nozzle is embedded into a viscoelastic support bath and extrudes
Created May 31, 2018, Updated December 8, 2022