Nanomechanical and nanotribological properties of hydrophobic fluorocarbon dielectric coating on tetraethoxysilane for electrowetting applications

Koumoulos, EP; Charitidis, CA; Papageorgiou, DP; Papathanasiou, AG; Boudouvis, AG

dc.contributor.author	Koumoulos, EP	en
dc.contributor.author	Charitidis, CA	en
dc.contributor.author	Papageorgiou, DP	en
dc.contributor.author	Papathanasiou, AG	en
dc.contributor.author	Boudouvis, AG	en
dc.date.accessioned	2014-03-01T02:11:30Z
dc.date.available	2014-03-01T02:11:30Z
dc.date.issued	2012	en
dc.identifier.issn	02578972	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/29921
dc.subject	Fluorocarbon	en
dc.subject	Mechanical integrity	en
dc.subject	Multilayer	en
dc.subject	Nanoindentation	en
dc.subject	Nanoscratch	en
dc.subject	Thin coating	en
dc.subject.other	Angle modulation	en
dc.subject.other	Applied loads	en
dc.subject.other	Critical load	en
dc.subject.other	Device design	en
dc.subject.other	Dielectric coatings	en
dc.subject.other	Dielectric layer	en
dc.subject.other	Elastic recovery	en
dc.subject.other	Electro wetting	en
dc.subject.other	Film adhesion	en
dc.subject.other	Friction mechanism	en
dc.subject.other	Improved reliability	en
dc.subject.other	In-situ	en
dc.subject.other	Information concerning	en
dc.subject.other	Lateral stress	en
dc.subject.other	Low voltages	en
dc.subject.other	Mechanical integrity	en
dc.subject.other	Multilayer structures	en
dc.subject.other	Nano-identation	en
dc.subject.other	Nano-indentation measurements	en
dc.subject.other	Nano-scratch	en
dc.subject.other	Nanotribological properties	en
dc.subject.other	Plastic regions	en
dc.subject.other	Thin coating	en
dc.subject.other	Top coating	en
dc.subject.other	Adhesion	en
dc.subject.other	Bond strength (materials)	en
dc.subject.other	Contact angle	en
dc.subject.other	Elasticity	en
dc.subject.other	Fluorocarbons	en
dc.subject.other	Hydrophobicity	en
dc.subject.other	Multilayers	en
dc.subject.other	Nanoindentation	en
dc.subject.other	Nanotechnology	en
dc.subject.other	Wetting	en
dc.subject.other	Coatings	en
dc.title	Nanomechanical and nanotribological properties of hydrophobic fluorocarbon dielectric coating on tetraethoxysilane for electrowetting applications	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.surfcoat.2012.01.034	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.surfcoat.2012.01.034	en
heal.publicationDate	2012	en
heal.abstract	Low voltage electrowetting (EW) systems are typically made of stacks of an insulating dielectric layer underneath a hydrophobic top coating. Of importance here is the strength of adhesion of the coating on the dielectric, investigated through nanoidentation and nanoscratch testing. Improvement of the adhesion strength of the hydrophobic top coating to the main dielectric was attempted through a fluorocarbon interlayer and the stack exhibited improved adhesion strength proven by nanoscratch testing. The difference between the scratch and post-scratch curve corresponds to the elastic recovery of the films, making nanoscratch testing a reliable technique for defining the elastic and plastic regions of thin coatings. The friction mechanisms in accordance with applied load were determined. Additionally, nanoindentation measurements were performed in order to define the hardness and the elastic modulus of the multilayer structure (thickness of layers of few nm). Moreover, the elastic recovery of the stack was investigated and the residual imprints were revealed through SPM imaging. Nanoscratch can be used for a plethora of tests, where a single scratch is useful for critical load, film adhesion and mar studies. Nanoscratch data, coupled with in-situ images, provide detailed information concerning a material's behaviour under simultaneous normal and lateral stresses. The purpose of this work is to investigate the mechanical integrity of an EW device design i.e. contribution of each layer of the stack to the total mechanical integrity. This design is advantageous since it exhibits resistance to dielectric breakdown, higher contact angle modulation range and improved reliability in multiple EW tests. © 2012 Elsevier B.V.	en
heal.journalName	Surface and Coatings Technology	en
dc.identifier.doi	10.1016/j.surfcoat.2012.01.034	en
dc.identifier.volume	206	en
dc.identifier.issue	19-20	en
dc.identifier.spage	3823	en
dc.identifier.epage	3831	en