Energy Harvesting
Garment harvesting is measured in microwatts. The useful question is not how much power, but how long to fill the capacitor.
— µW
Usable output at the stated cycle rate
Energy density per cycle depends entirely on how hard and how far the patch is actually strained in that garment position — a figure measured on a shaker rig will not survive being sewn into a sleeve. Measure it in situ before sizing anything downstream.
Piezoelectric Fabric Energy Harvesting Estimator — free, with the formula and a worked example, at Textile School.