Tamoghna Saha
| tsaha@ncsu.edu M.Tech, Chemical Engineering, 2016 Indian Institute of Technology, Dhanbad, Jharkhand B.Tech, Chemical Engineering, 2014 SRM University, Chennai, Tamil Nadu |  |
Research Focus:
My research focuses on developing new principles for the design of flexible, non-invasive and continuous wearable sweat sampling devices, that are capable of withdrawing sweat under both sedentary and actively perspiring conditions using osmotic pressure difference for pumping, and evaporation for liquid disposal. The device that we are developing in the lab is composed of silicone, polyacrylamide hydrogel patch, and paper microfluidic conduit with a site of evaporation at the end (evaporation pad). The hydrogel is equilibrated with glycerin, glucose, or NaCl solution to build up the desired osmotic strength. We investigate their operation using dye (a model biomarker). In-vitro testing with gelatin-based model skin platform revealed that both glucose and glycerin infused gels facilitate high accumulation on the evaporation pad, with glucose having the highest driving pressure. Parameters including the dimensions of the paper channel, hydrogel area and paper porosity also affect the cumulative dye collection. Human trials using prototype devices containing gels infused with glucose show potential to extract sweat and analyze it for lactate under both resting and non-resting conditions within a period of two hours. This sweat sampling concept can be integrated with continuous sensing using enzymatic electrochemical sensors. We chose lactate as a concept demonstrator, as sweat appears to be a much more informative medium for lactate quantification than blood. The ability to measure lactate is interesting for monitoring metabolism and oxidative stress levels in athletes and military personnel.