Optically induced electrokinetics(OEK)-based technologies,which integrate the high-resolution dynamic addressability of optical tweezers and the high-throughput capability of electrokinetic forces,have been widely use...Optically induced electrokinetics(OEK)-based technologies,which integrate the high-resolution dynamic addressability of optical tweezers and the high-throughput capability of electrokinetic forces,have been widely used to manipulate,assemble,and separate biological and non-biological entities in parallel on scales ranging from micrometers to nanometers.However,simultaneously introducing optical and electrical energy into an OEK chip may induce a problematic temperature increase,which poses the potential risk of exceeding physiological conditions and thus inducing variations in cell behavior or activity or even irreversible cell damage during bio-manipulation.Here,we systematically measure the temperature distribution and changes in an OEK chip arising from the projected images and applied alternating current(AC)voltage using an infrared camera.We have found that the average temperature of a projected area is influenced by the light color,total illumination area,ratio of lighted regions to the total controlled areas,and amplitude of the AC voltage.As an example,optically induced thermocapillary flow is triggered by the light image-induced temperature gradient on a photosensitive substrate to realize fluidic hydrogel patterning.Our studies show that the projected light pattern needs to be properly designed to satisfy specific application requirements,especially for applications related to cell manipulation and assembly.展开更多
基金This study was partially supported by the NSFC/RGC Joint Research Scheme(Project Nos.51461165501 and CityU132/14)the National Natural Science Foundation of China(Project Nos.61522312,61433017,and 61673278)+1 种基金the Shenzhen Science and Technology Innovation Commission Municipality(Project Nos.JCYJ20170818105431734 and JCYJ20150828104330541)the CAS FEA International Partnership Program for Creative Research Teams,and the Hong Kong Research Grants Council(Project Nos.CityU 116912,and 9041928).
文摘Optically induced electrokinetics(OEK)-based technologies,which integrate the high-resolution dynamic addressability of optical tweezers and the high-throughput capability of electrokinetic forces,have been widely used to manipulate,assemble,and separate biological and non-biological entities in parallel on scales ranging from micrometers to nanometers.However,simultaneously introducing optical and electrical energy into an OEK chip may induce a problematic temperature increase,which poses the potential risk of exceeding physiological conditions and thus inducing variations in cell behavior or activity or even irreversible cell damage during bio-manipulation.Here,we systematically measure the temperature distribution and changes in an OEK chip arising from the projected images and applied alternating current(AC)voltage using an infrared camera.We have found that the average temperature of a projected area is influenced by the light color,total illumination area,ratio of lighted regions to the total controlled areas,and amplitude of the AC voltage.As an example,optically induced thermocapillary flow is triggered by the light image-induced temperature gradient on a photosensitive substrate to realize fluidic hydrogel patterning.Our studies show that the projected light pattern needs to be properly designed to satisfy specific application requirements,especially for applications related to cell manipulation and assembly.
