A 1 square inch PCB module with 2 tiny solar cells, a highly efficient Li-Ion charger and with 3.3V and 1.8V output by Jasper Sikken:
This is a 1×1 inch PCB module with two tiny solar cells, a highly efficient Li-Ion battery charger and with two regulated outputs (3.3V and 1.8V). It is unique because it is an easy to manufacture tiny module that other hackers can drop in their PCB design or bread board. Bessides it harvests enough power from indoor light to power a simple BLE or LoRa sensor.
The challenge is to design a TINY module that easily interfaces to other projects. I selected tiny surface mount solderable solar cells, a highly integrated energy harvesting IC, and left out the battery. The board has castellated vias so it can be surface mount soldered onto a mother PCB as well as soldered onto 0.1″ headers to be used in a bread board.
Tiny Solar Energy Module (TSEM) – [Link]