Inkjet Printing of Silica Aerogel for Fabrication of 2-D Patterned Thermal Insulation Layers

Aerogels have the lowest thermal conductivity (< 0.2 W m⁻¹ K⁻¹) among known materials owing to the presence of pores, which constitute over 90% of the structure. Aerogels have mainly been commercialized for use as a thermal insulation material for building applications, such as walls and pipes. Herein, a silica aerogel thin film was fabricated by using a commercial and cost-effective HP inkjet printer. Next, silica aerogel ink was synthesized by mixing hydrophilic silica aerogel powder, solvent, and other organic additives. The thickness and pattern of the silica aerogel thin films were easily controlled by increasing the number of printing cycles and patterning by using a drawing software. The printed silica aerogel thin film had a smooth surface and thickness with well-distributed ink particles. Further, the aerogel had a unique structure comprising nanopores and nanonetworks. The thermal conductivity of the silica aerogel thin film was approximately 0.05 W m⁻¹ K⁻¹ at 30–300 °C. Inkjet printing of silica aerogels is expected to be a strong candidate for thermal insulating applications in micro-scale systems such as batteries and electronic chips.