The research objective of this proposal is to measure and model the native interfacial adhesion between polymers or metal coated polymers and bio-tissues using a contact mechanics approach. Bio-integrated electronics are a class of ultra-thin, ultra-soft, stretchable electronics which can conformably integrate with the soft, curvilinear and kinetic surfaces of bio-tissues for sensing, treatment, and communication. Conformable and robust binding between bio-tissues and electronics components can be obtained directly by such intrinsic adhesive interactions without recourse to intermediate adhesives or conductive gels. The proposed research will initiate a contact mechanics approach pertinent to bio-tissues through a combination of experiments and analytical/numerical modeling. We propose to develop a custom tissue tack tester capable of displacement control, measurement of contact load, and in situ monitoring of the contact area. Experimental data will be used in conjunction with contact mechanics models to determine the work of adhesion and traction-separation relations as the continuum representation of the adhesive interactions between various biotic-abiotic contact pairs. The effects of rate-dependence, tissue roughness, and bio-fluids will be considered.
Native adhesive interactions between electronic materials and bio-tissues as characterized by this research will be the key parameter in predicting interface reliability and in guiding the rational design of the mechanical structure of bio-integrated circuits. Outcomes from the proposed research will be assimilated into a new graduate level, school-wide, multidisciplinary course. Texas demographics are such that the undergraduate body at UT-Austin has a significant Hispanic representation (~17% in the Cockrell School of Engineering), who we have successfully encouraged to participate in our undergraduate outreach programs. The PI is a committee member of the UT Austin Women in Engineering Programs (WEP) and has dedicated herself as a mentor for underrepresented undergraduate and K-12 students.
