Gregory M. Gratson

Direct writing in three dimensions

Abstract The ability to pattern materials in three dimensions is critical for several emerging technologies, including photonics, microfluidics, microelectromechanical systems, and biomaterials. Direct-write assembly allows one to design and rapidly fabricate materials in complex three-dimensional shapes without the need for expensive tooling, dies, or lithographic masks. Here, recent advances in ink and laser writing techniques are reviewed with an emphasis on the push toward finer feature sizes. Opportunities and challenges associated with direct-write assembly are also highlighted.

Biomimetic silicification of 3D polyamine-rich scaffolds assembled by direct ink writing

We report a method for creating synthetic diatom frustules the biomimetic silicification of polyamine-rich scaffolds assembled by direct ink writing (DIW) [G. M. Gratson, M. Xu and J. A. Lewis, , 2004, , 386, ]. A concentrated polyamine-rich ink is robotically deposited in a complex 3D pattern that mimics the shape of naturally occurring diatom frustules, Ehrenberg (triangular-shaped) and (web-shaped). Upon exposing these scaffolds to silicic acid under ambient conditions, silica formation occurs in a shape-preserving fashion. Our method yields 3D inorganic-organic hybrids structures that may find potential application as templates for photonic materials, novel membranes, or catalyst supports.