Title : 
A Highly Flexible Superhydrophobic Microlens Array with Small Contact Angle Hysteresis for Droplet-Based Microfluidics
         
        
            Author : 
Im, Maesoon ; Kim, Dong-Haan ; Huang, Xing-Jiu ; Lee, Joo-Hyung ; Yoon, Jun-Bo ; Choi, Yang-Kyu
         
        
            Author_Institution : 
Korea Adv. Inst. of Sci. & Technol. (KAIST), Daejeon
         
        
        
        
        
        
            Abstract : 
This paper reports a highly flexible superhydrophobic and superhydrorepellent microlens array substrate with very low flow resistance. Even though the microlens array has no nanostructures, it shows hydrophobic property due solely to its geometrical effect. A contact angle of 165deg and hysteresis of 3deg are achieved on a flexible polydimethylsiloxane (PDMS) microlens array substrate with a Teflon (polytetrafluoroethylene) coating. Moreover, double-layered metals (Cr/Au) are sandwiched between the PDMS and Teflon layers for electrostatic or electrowetting-on-dielectric (EWOD) actuation. Due to its low flow resistance and superhydrophobicity, the array can be used as a microfluidic component that reduces external pressure and power consumption for mobility.
         
        
            Keywords : 
contact angle; flexible structures; hydrophobicity; microfluidics; polymer films; wetting; Teflon coating; contact angle hysteresis; double-layered metals; droplet-based microfluidics; electrostatic actuation; electrowetting-on-dielectric actuation; flexible polydimethylsiloxane microlens array; flow resistance; highly flexible superhydrophobic microlens array; polytetrafluoroethylene; superhydrorepellent microlens array; Chromium; Coatings; Electrostatics; Energy consumption; Gold; Hysteresis; Lenses; Microfluidics; Microoptics; Nanostructures;
         
        
        
        
            Conference_Titel : 
Micro Electro Mechanical Systems, 2009. MEMS 2009. IEEE 22nd International Conference on
         
        
            Conference_Location : 
Sorrento
         
        
        
            Print_ISBN : 
978-1-4244-2977-6
         
        
            Electronic_ISBN : 
1084-6999
         
        
        
            DOI : 
10.1109/MEMSYS.2009.4805422