Polymer-Derived Ceramic Materials from Thiol-ene Photopolymerizations

A novel reaction scheme for rapidly fabricating polymer-derived ceramic structures with high aspect ratios and with controlled shape and structure is described. The reaction scheme is based largely upon a thiol-ene photopolymerization mechanism. Thiol-ene photopolymerizations offer unique advantages including high polymerization speed in the presence of little or no photoinitiator, the ability to delay gelation, and the ability to achieve high double bond conversions. The addition of thiols to polymerizable vinyl-containing ceramic precursors further enables the formation of thicker structures than traditionally achieved. Structures formed using this mechanism exhibit little warping, and upon pyrolysis the polymer structures are transformed into ceramic structures of a self-similar shape. In the pyrolysis step, structures formed using this novel mechanism exhibit shrinkage and mass loss values similar to those produced from typical ceramic precursors. Further, the photolithographic process described here is readily extendable to make complex three-dimensional ceramic microstructures and microdevices.