Mechanical assessment of soft biological tissues and organs has broad relevance in clinical diagnosis and treatment of disease. Existing characterization methods are invasive, lack microscale spatial resolution, and are tailored only for specific regions of the body under quasi-static conditions. Here, we develop conformal and piezoelectric devices that enable in vivo measurements of soft tissue viscoelasticity in the near-surface regions of the epidermis. These systems achieve conformal contact with the underlying complex topography and texture of the targeted skin, as well as other organ surfaces, under both quasi-static and dynamic conditions. Experimental and theoretical characterization of the responses of piezoelectric actuator–sensor pairs laminated on a variety of soft biological tissues and organ systems in animal models provide information on the operation of the devices. Studies on human subjects establish the clinical significance of these devices for rapid and non-invasive characterization of skin mechanical properties.
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Research supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award # DE-FG02-07ER46471, through the Frederick Seitz Materials Research Laboratory at the University of Illinois at Urbana-Champaign. C.D. thanks Cavit Dagdeviren and YongAn Huang for their useful suggestions in device design, and V. Merkle for her assistance during DMA tests of ex vivo organ tissues. M.M. acknowledge support from the European Union (ERDF) and the Free State of Saxony via the ESF project 100098212 InnoMedTec. M.M. thanks G. Cuniberti from TU Dresden for fruitful discussions and for supporting an internship by J.A.R.
The authors declare no competing financial interests.
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Dagdeviren, C., Shi, Y., Joe, P. et al. Conformal piezoelectric systems for clinical and experimental characterization of soft tissue biomechanics. Nature Mater 14, 728–736 (2015). https://doi.org/10.1038/nmat4289
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