Nanoscale Measurements of Water Loss during Desiccation of Biological Cell Suspensions

摘要

There is an urgent need to protect and conserve the endangered species of the world. Desiccation, or the phenomenon of anhydrobiosis, offers the attractive possibility of low cost, long term storage of reproductive tissues and cells from endangered species at ambient temperatures. Biophysical optimization of anhydrobiosis procedures requires dynamic and accurate quantification of the rate of moisture loss during a prescribed desiccation protocol. Engineered microstructures can serve as a multifunctional and highly sensitive method to measure the rate of moisture loss. This study presents a novel ultrasound based (resonant) mass sensor to quantify water loss during a drying process by measuring the corresponding shift in the resonant frequency of a micromachined vibrating structure. To model the proposed ultrasound based sensor, we performed a static (stress) and dynamic (frequency change with change in imposed mass) analysis. The results suggest that by tailoring the dimension of the vibrating element appropriate sensitivity can be achieved.