SensNews June 2020

23 Sensor100 2020 Interest in Sweat Sensors A another device that claims to monitor health conditions in the body using a person's sweat has been developed by Penn State and Xiangtan University researchers, accord- ing to Huanyu "Larry" Cheng, assistant professor of engineering science and mechanics, Penn State. In sweat we have a lot of biomarkers like pH and glucose that will be a really nice indicator for disease progression or diagnostics," Cheng said. The device will be on a patch ap- plied to the skin near sweat glands. It consists of a small vial containing multiple chambers that has a hydro- phobic—water repelling—valve near the opening made of silicone rubber. The channel has a hydrophilic—water attracting—coating for easy collec- tion of the sweat. On-the-spot anal- ysis can be done using a colorimetric approach in which a color-coded analyte is preplaced in the various chambers.This sensitive chemical responds to the pH or glucose level and can be read by the naked eye or a photo taken with a smart- phone.Also, the researchers can analyze the sweat at different time points using differ- ent chambers—called chrono-sampling. PhysOrg News June 23 [It is difficult to see the value of this development. Sweat analysis is an established diagnostic technique for cystic fibrosis and it may have value in assessing dehydration levels in soldiers, firemen and perhaps elite athletes. What health conditions measuring sweat glucose and pH is for isn't clear to us. Sensors for sweat are entirely possible from an engineering standpoint and there are many of them, but what purpose they have is less obvious. Sensor100]