Study of PDMS as Dielectric Layer in Electrowetting Devices
An electrowetting-on-dielectric (EWOD) device by using Polydimethylsiloxane (PDMS) as dielectric layer has been fabricated. Aluminium metal film is used for EWOD electrode fabrication. Teflon AF 1600 thin film is coated to improve hydrophobicity and reduce liquid sticking (found in PDMS surface). Both PDMS and Teflon layer is deposited by spin coating. Direct coating of Teflon, on top of PDMS layer, results in poor quality film, because of inherent hydrophobic nature of PDMS. So, Oxygen plasma treatment of PDMS surface is carried, before Teflon coating. Movement of water droplet (conductivity: 250 μ S/m) is obtained at 150 V DC voltage supply. Present study demonstrates a simple, cost and time effective fabrication procedure for EWOD device.
KeywordsElectrowetting-on-dielectric (EWOD) PDMS Digital microfluidics Oxygen plasma treatment
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The authors would like to thank Mr. Pradip Kumar Dey, Mr. Dipankar Mandal and Mr. Subir Dasgupta connected to MEMS & Microelectronics Lab of ATDC, IIT Kharagpur for their help. The authors are thankful to Department of Biotechnology, Government of India for financial assistance and support to carry out the research work (Project:BT/PR3713/MED/32/203/2011).
- 1.J. Berthier, Microdrops and Digital Microfluidics. William Andrew Inc., Norwich, New York, USA, (2008).Google Scholar
- 5.S. Sohail and K. Biswas, `A novel approach for droplet position sensing in electrowetting devices’, Accepted in IEEE SENSOR 2013, November 3-6, Baltimore, Maryland, USA.Google Scholar
- 6.L. Hong, S. Dharmatilleke, D. K. Maurya, and A. A. Tay, Microsystem technologies, 16, no. 3, 449-460 (2010).Google Scholar
- 7.M. Abdelgawad, and A. R. Wheeler, Advanced Material, 21, 920-925 (2009).Google Scholar