title: Electrowetting without external voltage using paint-on electrodes.
abstract: Electrowetting uses voltage to manipulate small volumes of fluid for applications including lab-on-a-chip and optical devices. To avoid electrochemical reactions, a dielectric often separates the fluid from the electrode, which has the undesired effect of adding processing steps while increasing the voltage necessary for electrowetting. We present a new method to dramatically reduce the complexity of electrode and dielectric fabrication while enabling multiple performance advances. This method relies on a self-oxidizing paint-on liquid-metal electrode that can be fabricated in minutes on rigid, rough, or even elastic substrates, enabling low operation voltages (<1 V), and self-healing upon dielectric breakdown. Furthermore, due to the non-negligible 'potential of zero charge', electrowetting occurs by simply short circuiting the electrodes. This work opens up new application spaces for electrowetting (e.g. stretchable substrates, soft and injectable electrodes) while achieving large changes in contact angle without the need for an external power supply.
authors.affiliation: Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905, USA. mddickey@ncsu.edu.
authors.forename: Collin B
authors.identifier: 0000-0003-1880-5870
authors.initials: CB
authors.lastname: Eaker
authors.affiliation: Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905, USA. mddickey@ncsu.edu.
authors.forename: Ishan D
authors.initials: ID
authors.lastname: Joshipura
authors.affiliation: Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905, USA. mddickey@ncsu.edu.
authors.forename: Logan R
authors.initials: LR
authors.lastname: Maxwell
authors.affiliation: Department of Electrical Engineering and Computing Systems, University of Cincinnati, Cincinnati, OH 45221-0030, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Heikenfeld
authors.affiliation: Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695-7905, USA. mddickey@ncsu.edu.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Dickey