Medical-grade patches use either a matrix system, where the active ingredient is distributed evenly throughout the patch, or a reservoir system, which controls release from a central chamber.

The main ingredients The Patch Brand claims are in its sleep patch are fairly straightforward — melatonin, valerian root, vitamin B2, among a few others — and I felt comfortable giving it a whirl.

Why patch-based wearable devices for medical monitoring are gaining more research attention. How these devices are fabricated to achieve specific objectives. How some wearable devices implement ...