Antifouling surface treatments for microfluidic applications
To remediate bioparticle losses from adhesion to microfluidic device surfaces, we have implemented polyethylene glycol (PEG)-type coatings by self-assembled monolayer and plasma-polymerizing deposition techniques. A variety of substrates representative of device materials in contact with bioparticle solutions were subjected to static microbial adhesion tests. We saw significant reduction in B. thuringiensis adhesion for both types of PEG coatings and reduction in B. globigii adhesion for the plasma-polymerized coating. Furthermore, we have demonstrated that both PEG-type coatings on MEMS traveling-wave arrays are effective at reducing adhesion to polystyrene beads as well as both Bacillus species. Results from both experiments have provided groundwork for in-situ experiments in flow environments for assessment of bioparticle recovery and adhesion to electrically conductive parallel flow plates. Spectrophotometry is used to gauge bioparticle concentration before and after circulation within the flow chamber. Open circuit voltage is monitored to investigate electrical behavior affected by bioparticle adhesion to the flow plates. Comparison of both measurements for parallel flow plates of different conductivities with and without our plasma-polymerized PEG coating will help corroborate and predict the degree to which bioparticle losses can be minimized.
Chang, N. E. ; Lean, M. ; Limb, S. Antifouling surface treatments for microfluidic applications. American Vacuum Society 53rd International Symposium and Exhibition; 2006 November; San Francisco; CA; USA.