>In the new smartwatch, a strip of specialized thin adhesive film collects tiny volumes of sweat, measurable in millionths of a liter. An attached sensor detect

>In the new smartwatch, a strip of specialized thin adhesive film collects tiny volumes of sweat, measurable in millionths of a liter. An attached sensor detects cortisol using engineered strands of DNA, called aptamers, which are designed so that a cortisol molecule will fit into each aptamer like a key fits a lock. When cortisol attaches, the aptamer changes shape in a way that alters electric fields at the surface of a transistor. While I'm quite interested in being able to track my cortisol levels, the physics and chemistry behind this invention is just absolutely fascinating. I'm definitely going to be following this work closely.