Harvest energy from ultra low current and high voltage source?

I have a sensor which can produce voltage upto 10 V but can only produce 50 nA of current. I tried to harvest energy using TI's BQ25570 evaluation board but the current is too low to kickstart the board. Also, the sensor is a high impedance source.

How can I harvest energy from this sensor?

Can I boost the current somehow? Would a Darlington pair work for this purpose?

• Do you really mean "harvest"? Maybe you want to measure it, or something? – Ale..chenski Mar 10 '19 at 4:07
• What is the source? You can probably get more energy more easily from ambient sources. Light, heat, broadcast or cellphone or mobile radio signals. Brownian motion is probably a better source :-). – Russell McMahon Mar 10 '19 at 11:46

• @Ale..chenski PP film cap should be fine. >100,000 M$\Omega$/uF. But leakage can come from lots of other places at that level. – Spehro Pefhany Mar 10 '19 at 4:37