University of California, Berkeley, USA
Department of Mechanical Engineering


Plenary Talk

Digital light manufacturing in multi-phase volumes of material

There is an increasing variety of instances in photopolymer additive manufacturing where the structuring of multi-phase volumes of material is desired. One example is the printing of intricate nanocomposite green bodies composed of silica nanoparticles in a photopolymer binder, where the photopolymer is subsequently thermally extracted and the component is sintered. Other potential examples include the incorporation of reinforcing fibers into a photopolymer precursor, the dispersion of biological cells into a directly printed hydrogel precursor, fluid encapsulation for controlled-viscoelasticity structures, and the ‘overprinting’ of polymeric geometries binding to pre-existing structures of another material. All of these processing capabilities are potentially relevant for the production of living, reconfigurable, or stimulus-responsive structures.

Volumetric additive manufacturing (VAM) is attractive for these applications because it is amenable to far higher-viscosity precursors than established layer-based printing processes, avoids exposing the precursor to substantial shear stresses during geometry formation, and lends itself to the entrainment or immersion of solid particles and objects within the precursor material. Among the emerging volumetric techniques is computed axial lithography, which delivers a light dose to a 3D material volume via tomographic reconstruction. A major challenge to be overcome in the volumetric processing of multi-phase materials is achieving effective control of the propagation of light, when occlusion, refraction, and scattering effects can all be significant. Additional concerns include the mechanical performance of material interfaces within the volume, and the effect of gravity on bodies dispersed within the volume. This talk will describe some recent results in addressing the optical and mechanical challenges in multi-phase VAM.

Biography:
Hayden Taylor is an Associate Professor of Mechanical Engineering at the University of California, Berkeley. His research spans the invention, modeling and simulation of manufacturing processes, with the aim of reducing materials and energy usage to support industrial decarbonization. Current research activities have the following themes: (A) processing of materials for sustainable construction, (B) multi-scale volumetric additive manufacturing, and (C) contact mechanics in semiconductor manufacturing. He holds B.A. and M.Eng. degrees in Electrical and Electronic Engineering from Cambridge University and a Ph.D. in Electrical Engineering and Computer Science from MIT.