Highly efficient semiconductor modules making controllable parallel microchannels for non-compressible hemorrhages

Nature makes the most beautiful solution to involuted problems.Among them,the parallel tubular structures are capable of transporting fluid quickly in plant trunks and leaf stems,which demonstrate an ingenious evolutionary design.This study develops a mini-thermoelectric semiconductor P-N module to create gradient and parallel channeled hydrogels.The modules decrease quickly the temperature of polymer solution from 20◦C to20◦C within 5 min.In addition to the exceptional liquid absorption rate,the foams exhibited shape memory mechanics.Our mini device universally makes the inspired structure in such as chitosan,gelatin,alginate and polyvinyl alcohol.Non-compressible hemorrhages are the primary cause of death in emergency.The rapid liquid absorption leads to fast activation of coagulation,which provides an efficient strategy for hemostasis management.We demonstrated this by using our semiconductor modules on collagen-kaolin parallel channel foams with their high porosity(96.43%)and rapid expansion rate(2934%).They absorb liquid with 37.25 times of the own weight,show 46.5-fold liquid absorption speed and 24-fold of blood compared with random porous foams.These superior properties lead to strong hemostatic performance in vitro and in vivo.

Constructal design of a rectangular parallel phase change microchannel in a three-dimensional electronic device

Based on constructal theory,a rectangular parallel phase change microchannel model in a three-dimensional electronic device(TDED)is established with R134a as the cooling fluid.Based on the minimization of a complex function(CF)composed of linear weighting sum of maximum temperature difference and pumping power consumption,constructal design of the TDED is conducted first;and then,maximum temperature difference and pumping power consumption are minimized by non-dominated sorting genetic algorithm-II methods.The results reveal that there exist an optimal mass flow rate(0.0012 kg/s)and a quadratic optimal aspect ratio(AR)(0.39)of the microchannel which lead to quadratic minimum CF(0.817).Compared with the original value,the CF after optimization is reduced by 18.34%.Reducing the inlet temperature of cooling fluid and microchannel number appropriately can help to enhance the overall performance of TDED.By using the artificial neural network and genetic algorithms in the toolboxes of Matlab software,the optimal AR gained in the Pareto solution set is located between 0.2–0.45.The smallest deviation index among three discussed strategies is 0.346,and the corresponding optimal AR is 0.413,which is selected as the optimal design strategy of the microchannel in the TDED under multiple requirements.The findings in this study can serve as theoretical guides for thermal designs of electronic devices.