3D-printed low-cost fabrication and facile integration of flexible epidermal microfluidics platform

Skin-mounted microfluidics devices have shown distinct advantages in sweat collection and analysis platform due to their multiple sweat treatment including sample collection, flow control, storage, analysis and expelling by special design in microfluidic networks. However, the fabrication of most reported wearable microfluidic devices with mechanical flexibility and elasticity mainly rely on soft-lithography technology whose implementation is limited by necessitating access to resource-intensive laboratory and costly facilities. Herein, we propose an accessible, low-cost fabrication and integration scheme, which renders flexible microfluidic architecture capable of performing reliable sweat collection and sensing. We utilize low-cost 3D-printing technology to rapidly yield positive mold of facile printable material (malt syrup) for personalized customization of microfluidic channels. An ingenious approach is also proposed to encapsulate microfluidic channel layer and integrate pH sweat sensor into the microfluidic device for dependable sweat collection and pH analysis. The proposed fabrication strategy of flexible and stretchable epidermal microfluidic sensor represents a low cost, reachable alternative to recently prevailing soft-lithography method, and hence significantly reduces the threshold of microfluidic development and manufacture.