Key points are not available for this paper at this time.
An autonomous power generator unit including two micropower sources and their management IC has been fabricated: a RF power receiver and a 1 V miniature thermogenerator combined with a micropower DC/DC up-converter are combined with a 78% efficiency manager and charger, and a 5 nW discharge monitor to manage and store the harvested energy in a 30 above-IC deposited microbattery.
Lhermet et al. (2008) studied this question.