Fabrication and Electrowetting Properties of Poly Si Nanostructure Based Superhydrophobic Platform

• Published in: Plasma chemistry and plasma processing Vol. 33; no. 4; pp. 807 - 816
• Main Authors: Rajkumar, K., Rajendrakumar, R. T.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.08.2013
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Classical Mechanics; Contact angle; Deposition; Droplets; Electric potential; Electrodes; Gold; Inorganic Chemistry; Mechanical Engineering; Nanostructure; Original Paper; Voltage; Electrowetting; Contact angle; Polysilicon and reactive ion etching; Superhydrophobic surface
• ISSN: 0272-4324; 1572-8986
• DOI: 10.1007/s11090-013-9462-8

Poly-silicon based superhydrophobic surface (water contact angle >150°) is being fabricated and its electrowetting properties have been studied. The polysilicon thin film has been deposited over patterned gold electrodes. The polysilicon film is structured to form nanoscale features using Reactive Ion Etching. A thin film of HfO 2 high k-dielectric is deposited over the structured polysilicon surface. The surface was chemically modified with Trichloro (1H, 1H, 2H, 2H-perfluorooctyl) silane (PFOS). Such a surface showed Superhydrophobic behavior with water contact angle of 172° and roll off angle <3°. The electrowetting properties of the fabricated device was studied by applying a DC voltage between the gold electrode and the droplet. The electrowetting commences when the applied voltage was 18 V and the contact angle is reduced to 152°. As the applied voltage was increased there was decrease in contact angles.