Enhanced Micro-scale Heat Transfer Methods For Vitrification

There are many problems in current methods of vitrification,such as low heat efficiency,low sample load and high pollution risk.In this paper,three enhanced micro-scale heat transfer methods have been applied to vitrification to address the problems,including microchannel,micro-jet,microchannel with impinging jet.It was expected to invent new devices for vitrification.The specific research contents are as follows:(1)A novel device based on microchannel heat transfer has been developed for vitrification.An experimental system was also developed to drive and control the flow of working fluids.The effects of operation condition,microchannel-chip sizes and concentrations of CPAs on thermal performance of the device have been investigated experimentally.Experimental results show that the highest cooling rate of the microchannel-aided device is 34825±2052 ?/min,the rewarming rate is up to 149500±10052 ?/min,and the range of sample load is 52?L-585?L.However,the device has a poor temperature uniformity during the experiment.(2)A novel device based on micro-jet impingement heat transfer has been developed for vitrification.The effects of operation condition,height and porosity on thermal performance of the device have been investigated experimentally.Experimental results show that the device has super high heat transfer efficiencies and a high temperature uniformity.With experimenting with 157?L sample solution,the cooling rate is high to 11456±456?/min,the highest rewarming rate is 130000± 11325?/min.However,the disadvantage of poor insulation performance of the device makes the experiment much difficult to operate.(3)A preliminary device based on hybrid microchannel/micro-jet impingement for vitrification has been established,the microchannel of which is in the shape of a spider web.And the thermal performance of the preliminary device has been investigated experimentally.Then,an optimized scheme with straight microchannels has been proposed.Numerical simulation research has been carried out to study the effects of the key structural parameters on thermal performance of the optimized scheme.Finally,based on the simulation results,a novel hybrid microchannel/micro-jet impingement aided device for vitrification has been developed.The effects of operation condition and thickness on thermal performance of the device have been investigated experimentally.The experimental results show that the device has high heat transfer efficiencies and an excellent temperature uniformity.The highest cooling rate in the experiments is 13270±986?/min,and the highest rearming rate is 17021± 1176?/min.The range of sample load is 110?L-440?L.In this paper,three kinds of enhanced micro-scale heat transfer methods have been applied for vitrification.Although the biological material experiments have not been carried out,and there are still drawbacks in the methods.But research results show that enhance micro-scale heat transfer methods for vitrification have unique advantages,and have the ability to realize the vitrification of large volume cell suspensions and tissues,which provides a reference for the innovation of the methods of vitrification.