Etched Silica Aerogels

Aerogel is a nanoporous material that has many unique properties including high surface area, high porosity, low density, and low thermal and electrical conductivity. In addition, silica aerogels are translucent and they interact with light in interesting ways. This light interaction has been an inspiration for artist Ioannis Michaloudis’s aerogel sculptures. It was recently discovered at Union College that is possible to etch onto the surface of an aerogel with a CO₂ laser cutter and produce interesting patterned aerogels. Experiments were performed to assess the effects of the CO₂ laser cutter settings (power and speed) on etching patterns for a variety of aerogel surfaces (smooth planar and roughened edges). Etching on the roughened edges created a 3D effect, making it look like the etching went through the aerogel. The etched aerogels were examined using a scanning electron microscope (SEM) to assess how the microstructure of the aerogel was affected by etching. At low magnification, the aerogels look fibrous and somewhat “moth-eaten” while at higher magnification the structure resembled an unetched aerogel. An aerogel-etched sculpture inspired by the work of Michaloudis and the discovery of the etching process was created. The sculpture consists of a mosaic of etched and unetched aerogel assembled in an acrylic frame to create a “U” for Union with a light casted on the aerogel creating a unique shadow.