Use of carbon dioxide as a solvent and water replacement for “dry” manufacturing in the microelectronics, industrials and pharmaceuticals processing industries

Team: Joseph DeSimone, Gunilla Jacobson
Planning (Scoping)

The global chemical industry manufactures more than 30 billion pounds of organic and halogenated solvents each year as process aids, cleaning agents, and dispersants. Manufacturing and related processes consume and contaminate even greater quantities of water. The cost to treat and dispose of this waste, as well as employee health and safety considerations, are driving a search for environmentally benign, cost-effective solutions. Carbon dioxide (CO2) is a non-toxic, inexpensive, widely available alternative for chemical and industrial manufacturing processes that require large amounts of solvents for cleaning and drying, such as the microelectronics industry. By pressurizing CO2 gas at 31°C it obtains the density of a fluid, in what is defined as a supercritical state. Supercritical CO2 (scCO2) can thereby replace organic solvents for cleaning. Since depressurization of the scCO2   into the gas phase leaves behind a dry surface the use of water for rinsing can be eliminated in the process. We investigated scCO2 in these applications: spray drying, nanoparticle formation, chemical reactions that rely on CO2 as a solvent or a reactant, and cleaning, deposition, and drying for microchip fabrication. We achieved promising results in the post processing of 3D printed systems with open channels and high aspect ratios. We showed that CO2 can remove residual resin from 3D-printed vascular systems and microfluidic-enabled microarray patches. We also demonstrated that it is feasible to load post-processed 3D-printed microarray patches with cargo for in vivo release via transdermal drug delivery. We will continue to explore replacing organic and aqueous liquids with alternatives that require lower quantities of organic solvents and generate less hazardous waste.