Origami Mask which require no glue or stapling. A4 paper and non latex silicon bands make a cheap and hygiene disposable mask.
Harvest a cheap electronic device for parts.
If you have an old tablet that doesn't work you can disassemble it and reuse some of its components. The Wi-Fi board could be very useful.
You have an old Hard Drive 2.5'' or 3.5'' left from your laptop or PC and you don't know what to do. Then turn it into a portable one.
Equipping the old-made (but not used) plotter with Bluetooth COM port. Then making the first PCB and case's backplate with it.
Low cost, self made, mobile and recycling materials from a printer
