Quantifying Desiccation in Glycerol–Agarose Hydrogels

Author(s):

Ella Willetts, W. David Hairston, and Christopher G. Sinks

Abstract:

Electromagnetic (EM) radiation-emitting devices are becoming more common in the world and on the battlefield with the use of radar, high-power radios, and other nonionizing radiation-emitting devices. We lack an efficient way to test safety and biological effects of EM, so we need admittance-matching tissue simulants to test for detrimental effects and develop protective measures. Some of the best candidates for the simulants are hydrogels due to their high-water content and tissue-similar mechanics. However, these gels can desiccate over time, changing their properties over the course of experimentation. A common solution is to add a humectant, which helps keep water bound in the hydrogel. In this work, we quantify how much of a common humectant, glycerol, changes equilibrium water content across a series of agarose-based hydrogels kept under strict environmental conditions. From this data, we can estimate how much glycerol is required to stabilize a tissue-simulant model under a given set of environmental conditions, allowing for better testing of EM response of tissue over a longer period of time.