title: Digital electrospray for controlled deposition.
abstract: Many novel functional structures are now fabricated by controlled deposition as a maskless, bottom-up fabrication technique. These applications require rapid and precise deposition of minute amounts of solutions/suspensions or their ultimate particle products in predefined patterns. The electrospray is a promising alternative to the commonly used inkjet printing because it can easily handle highly viscous liquid, avoid high shear rates, and has low risk of clogging. We demonstrate a proof-of-concept digital electrospray. This system consists of a 61-nozzle array microfabricated in silicon and a 61-element digital extractor fabricated using flexible polyimide substrates. "Digital" refers to the state of each electrospray source that can be tuned either on or off independently and responsively. We showed a resolution of 675 mum and a response frequency up to 100 Hz. With similar design and industry standard fabrication procedures, it is feasible to scale up the system to O(1000) sources with spatial resolution better than 250 mum and a O(kHz) response frequency. The latter is controlled by the viscous damping time.
authors.affiliation: Department of Mechanical Engineering, Yale University, 9 Hillhouse Ave., New Haven, Connecticut 06520, USA.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Deng
authors.forename: C Mike
authors.initials: CM
authors.lastname: Waits
authors.forename: Alessandro
authors.initials: A
authors.lastname: Gomez
mesh_terms: D004548:Elasticity; D004566:Electrodes; D004574:Electromagnetic Fields; D004581:Electronics / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D055616:Microtechnology; D010781:Photography; D012825:Silicon; D012996:Solutions; D013535:Suspensions; D013997:Time Factors; D014783:Viscosity
chemical_list: D012996:Solutions; D013535:Suspensions; D012825:Silicon