I wonder is it not possible to transmit power through the body. It seems janky anyway how does the battery pack on your pocket connect to your body. Wireless has loss. Watch battery pack that uses a laser shooting at the glasses ha. Also clothes that harvest power maybe contacts to body.

The human body consumes merely ~2000 calories a day. Really not that much energy, about the same as a 100W light bulb.

Even if you can capture every single bit of extra energy from a tshirt, you'd end up with a tiny fraction of 100W. Certainly not enough to power a mobile device like this.