Portable resonant acoustic rheometry system enables rapid and integrated acoustic-mechanical characterization of soft biomaterials

Resonant acoustic rheometry (RAR) is a contactless technique for measuring viscoelasticity of soft materials based on the resonant surface waves generated on a sample surface using a dual-mode ultrasound technique. This study reports the development and validation of a portable RAR system for enabling rapid, co-localized, and simultaneous viscoelastic and acoustic characterization of multiple soft material samples. Our results reveal strong correlation of RAR measurements of Young's modulus and viscosity in polyethylene glycol hydrogels with the storage and loss modulus measured using a dynamic mechanical analysis instrument. In addition, RAR measurements of Young's modulus and viscosity exhibited positive correlation with the speed of sound and acoustic attenuation measured during RAR. These results expand the utility of RAR as an integrated tool for acoustic-mechanical characterization of soft viscoelastic materials.