Wearable gauges fitness through stress hormones in your sweat

Wearable gauges fitness through stress hormones in your sweat

A typical sensor looks for the positive or negative charge in molecules, but that’s not really an option with a chargeless substance like cortisol. The researchers tackled this with a membrane that binds only to cortisol and lets regular charged molecules pass through. The sensor then measures the cortisol-carrying molecules trapped by the membrane, rather …