On-chip cryopreservation of cells

MEMS (microelectromechanical systems)-assisted, on-chip cryopreservation of biological cells under low temperature environments has been successfully demonstrated. In the proof-of-concept experiment, microheaters are used as both the resistive heating elements and temperature monitors to control the temperature profile of microenvironments under liquid nitrogen cooling. A two-step cryopreservation protocol is applied to the controlled microenvironment and 7/spl sim/12 times better survival rate has been achieved for yeast cells after the air thawing process as compared with a reference sample without the MEMS-assisted control. As such, this scheme could have potential applications in on-chip cryopreservation processes, including those for sperm, embryo, or lab-on-a-chip.