I wanted to design a simple contactless door opener, well it got complicated.
I run a research group that does work on microbial infections including COVID-19. I wanted to give my team some additional protective equipemnt to use in their everyday life. So this contactless device is three pieces plus some extra filament pegs gluded together.
It can push doors, carry bags, turn lever doorknobs, close bathroom stall latches, punch buttons, be used with a touch screen, and can even hold cards out. All without bringing you in contact with its touchpoint surfaces which is an issue with a lot of the ones out there.
The problem with FDM prints and sterility is that they have surface features that allow bacteria and viruses to hide in, even when sprayed with disinfectants. Although I would recommend still disinfecting with 60% ethanol, the best option is to have the touchpoints covered when not in use. For the designs that have a case included, they would require two hands to operate (one to hold the case the other to use the device).
One of the best designs I've seen so far to help with this is the switchblade design of the Door Opener Advance by crashdebug: https://www.thingiverse.com/thing:4285461
That being said, I didn't like the fact that it was not something easy to do with one hand and it still had potential contact risk in the handle when opening and closing the door opener.
My design has a guard built into the handle, can be printed and assembled, without supports, in PETG for strength, in under an hour. If you want to have the ability to use a touch screen I've included that as well, just print the alternative pusher tool and the corresponding capacitative skin (need to use capacitative PLA). I have another design in the works, this one with a thumb switch and one without and a simpler case shape, the thumb bumps do give a better user feel in the hand.
I would recommend printing both and testing out which feels right for you.
I did print everything in 100% infill to extra strength. I'm able to lift a 45lb weight in a bag without it breaking, but that might be overkill.
Enjoy and let me know if you have any suggestions.
List of materials used - ProtoPasta conductive/capacitative PLA (two options below): - 150g - https://amzn.to/3hTGAKk - 500g - https://amzn.to/37TQ6sp - PETG - I used Prusa Translucent Violet - a good alternative in the States - https://amzn.to/3hRHmaV - also black https://amzn.to/3fWhE2T - BSI extra thick cyanoacrylate - https://amzn.to/37TjVJw