An Electrically and Thermally Conductive Stage Applied to a 2.45-GHz In Vitro Exposure Setup Loaded With T25 Flasks
Jianxun Zhao, Xicheng Wei, Shuai Li, X M Zhang · IEEE Transactions on Microwave Theory and Techniques · 2024
An electrically and thermally conductive (ETC) stage has been designed and fabricated to reduce exposure inhomogeneity, increase exposure efficiency, and suppress temperature elevation for cell suspension and monolayer experiments. A 2.45-GHz waveguide cavity loaded with a pair of ETC stages and T25 flasks with culture medium was numerically and experimentally tested. Compared with a polystyrene stage, the ETC stage made of aluminum achieves a 36.6% reduction of inhomogeneity, an 82.2% increase of efficiency, and a 59.4% suppression of temperature elevation for cell suspension exposure. Cell monolayer exposure benefits from the ETC stage with inhomogeneity reduced by 69.5% and temperature elevation suppressed by 28.2%. The performance of the ETC stage is detailed by considering the positional error of the culture medium and the application of adaptive temperature control instead of conventional temperature control to enlarge the specific absorption rate (SAR) of nonthermal exposure. The electrical and thermal functions of the ETC stage are comprehended by characterizing$E$-fields,$H$-fields, an electric current, electromagnetic energy flux, temperature elevations, heat flows, and fluid currents. The ETC stage is compared with an alumina ceramic slab on exposure inhomogeneity, exposure efficiency, and heat dissipation.