Dear Soheil,

having a uniform temperature distribution such as the 37°C all over in the body will not work for that purpose. You need a temperature difference/gradient for setting up a voltage.

Please have a look at the link:

https://en.wikipedia.org/wiki/Thermoelectric_effect

In order to exploit thermal energy you need a temperature difference between two heat baths, for example the difference between inside and outside the body.

Here are alternative energy sources for implants.

https://www.nextbigfuture.com/2016/08/implantable-neural-dust-powered-by.html

https://www.medgadget.com/2014/05/new-wireless-technology-beams-power-into-body-to-energize-tiny-implantable-devices.html

http://www.pnas.org/content/early/2014/05/14/1403002111

https://www.nextbigfuture.com/2017/08/antennas-100-times-smaller-than-today-could-enable-tiny-brain-implants-and-other-breakthroughs.html

http://www.impactlab.net/2016/02/22/powering-brain-implants-with-thin-film-wireless-power-transmission-system-and-without-wires/

https://www.eurekalert.org/pub_releases/2012-01/cwru-ibc010612.php

https://phys.org/news/2016-01-cellulose-nanogenerators-day-power-implanted.html

https://phys.org/news/2012-02-biofuel-cell-electricity-implanted-false.html

https://phys.org/news/2017-10-ingestible-devices-movement-ingestion-stomach.html

https://www.popsci.com/technology/article/2011-02/stretchable-nanogenerators-could-expand-and-contract-your-every-breath-using-lungs-power-medical-impl

https://www.medgadget.com/2014/06/flexible-implantable-generator-uses-bodys-own-motion-to-power-pacemaker-video.html

https://www.newscientist.com/article/dn24906-bendy-implant-harnesses-the-power-of-your-beating-heart/

Regards,

Joachim

The chip cannot be powered this way, it doesn't comply with thermodynamics laws.