This review article examines digital microfluidic systems that manipulate droplets through surface anisotropy.These systems are categorized as surface tension driven or contact line driven.Surface tension driven syste...This review article examines digital microfluidic systems that manipulate droplets through surface anisotropy.These systems are categorized as surface tension driven or contact line driven.Surface tension driven systems include electrowetting on dielectric,Marangoni flow on microheater arrays,and chemical gradient surfaces,whereas contact line driven systems include anisotropic ratchet conveyors,nanostructured Parylene ratchets,and tilted pillar arrays.This article describes the operating principles and outlines the fabrication procedures for each system.We also present new equations that unify several previous models of contact line driven systems.The strengths and weaknesses of each system are compared,with a focus on their ability to perform the generation,switching,fusion,and fission of droplets.Finally,we discuss current and potential future applications of these systems.展开更多
基金This work was supported by National Science Foundation grant ECCS-1308025 Droplet Ratchets:Low Cost Digital Microfluidics.HRH would like to acknowledge the National Defense Science and Engineering Graduate Fellowship(NDSEG)for their support of this workFabrication of ARCs was performed at the Washington Nanofabrication Facility(WNF),a National Nanotechnology Coordinated Infrastructure(NNCI)site at the University of Washington,which is supported in part by the National Science Foundation(awards 1542101,1337840 and 0335765),the Washington Research Foundation,the M.J.Murdock Charitable Trust,Altatech,ClassOne Technology,GCE Market,Google and SPTS.
文摘This review article examines digital microfluidic systems that manipulate droplets through surface anisotropy.These systems are categorized as surface tension driven or contact line driven.Surface tension driven systems include electrowetting on dielectric,Marangoni flow on microheater arrays,and chemical gradient surfaces,whereas contact line driven systems include anisotropic ratchet conveyors,nanostructured Parylene ratchets,and tilted pillar arrays.This article describes the operating principles and outlines the fabrication procedures for each system.We also present new equations that unify several previous models of contact line driven systems.The strengths and weaknesses of each system are compared,with a focus on their ability to perform the generation,switching,fusion,and fission of droplets.Finally,we discuss current and potential future applications of these systems.
