If you have a 3D printer or know someone with one, there are a couple designs that can be 3D printed or the 3D printed parts can be combined with commonly available materials:
(Ironically, the only friend I have with a 3d printer is over the nearby NSW/QLD border that has been closed due to the pandemic crisis. Not an insuperable problem however).
https://www.prusa3d.com/covid19/
https://www.forbes.com/sites/tjmccue/2020/03/24/calling-all-...
https://onezero.medium.com/people-around-the-world-are-3d-pr...
https://www.dezeen.com/2020/03/29/creality-3d-printed-buckle...
https://3dprintingcenter.net/2020/03/19/scientists-from-the-...
https://rp95.cz/en/