Title: Interface Profile Near The Contact Line In Electro-wetting On Dielectric

Speaker: Prof. Weiqing Ren (Department of Mathematics , National University of Singapore )

Time: 16:00-19:00 pm, June 25 

Location: Room 200-9, Sir Shaw Run Run Business Administration building, School of Mathematical Sciences, Yuquan Campus

Abstract: We consider a charged droplet sitting on a dielectric substrate and study the static profile of the  interface near the contact line. We first derive the governing equations using the principle of minimum energy, thendiscuss the distinguished limit of the model as the dimensionless parameters β and d go to zero with d/β = O(1), where β  is the (rescaled) square of the imposed electrical potential and d is the thickness of the insulator. Analysis of the inner problem, which governs the interface profile near the contact line, shows the existence of a well-defined apparent contact angle. Significant bending of the interface is observed near the contact line. The apparent contact angle depends on the applied electrical potential and the thickness of the insulator, and the relation agrees well with the Lippmann-Berge equation.  

Contact Person: Qinghai Zhang (qinghai@zju.edu.cn)