https://www.cnx-software.com/2022/08/22/femto-tiny-raspberry-pi-rp2040-module/
Femto is a tiny 12x12mm Raspberry Pi RP2040 module - CNX Software
Aug 29, 2022 - Mirek Folejewski has designed the ridiculously tiny Femto module based on the Raspberry Pi RP2040 microcontroller with a size of just 12x12mm, and still
raspberry pi rp2040femtotiny12x12mm