A Low-Cost, Composite Collagen-PDMS Material for Extended Fluid Retention in the Skin-Interfaced Microfluidic Devices (Postprint)
Journal Article - Open Access,18 Sep 2018,27 Jun 2020
State University of New York at Binghamton Binghamton United States
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The advancement of soft, wearable microfluidic devices relies on the microfabrication of polydimethylsiloxane PDMS using soft lithography techniques. However, thin 3D microstructures made of PDMS limit long-term storage of aqueous samples and reduce the accuracy of onboard sensing modalities within the platform because of the materials high permeation of water vapor. We studied a composite material of collagen microparticles and PDMS that greatly reduces water evaporation while maintaining the properties of a soft elastomer required for skin-interfaced microfluidics. The collagen-PDMS material is biocompatible, affordable, and non-toxic. We reduced permeability by 80.2 by building a film containing 30 wt collagen microparticles. Mechanical properties, such as elastic modulus and bonding efficacy, can vary as a function of particle concentration in the films. The skin-interfaced collagen-PDMS microfluidic devices increase sweat retention by 45 through 9 h compared with pure PDMS. This material can greatly improve the long-term sample storage of epidermal devices.