This machine-washable sensor will let you wear your heart on your sleeve

Researchers at Swiss Federal Laboratories for Materials Science and Technology, Dubendorf, debuted a new fiber optic material in the Journal of the Royal Society Interface that can be woven, knitted or embroidered into existing fabrics. The material can be used to create comfortable, flexible wearable sensors that can blend right in to existing clothing. It's even machine washable. The material contains both embedded LED lights and a heart rate detector. It also has enough leakage to let light from the LEDs shine onto the skin and bounce back into the detector.