idea for a simple and thin contact based sensor

Hello instructacles,

I'm trying to build a simple contact-based set of sensors embedded in card board, paper or thin plastic sheets.

I want to make a simple game for my kids that could detect/react to the presence/absence of some random items positionned on such a board? (empty glass bottle of coke, cereal box, shampoo bootle, you name it)

Ideally i would use something like those books for kids where they have metallic threads "printed" on think plastic sheets and when you press them, it triggers a music. But i dont know how to print metal basically. don't really know how to get started.
I was thinking of sewing conductive thread but i'm not really sure it would work.

I have seen many attempts with aluminium foil (ex: https://www.instructables.com/id/Interactive-Art-With-Scratch-and-Makey-Makey/) but those are based on the fact that a human finger touches them (basically it uses the conductivity of skin), whereas in my game i was to use the weight of random objects from the house (in the 50g to 500g range typically)

Any idea how i should get started ?

thanks
fourchu



Downunder35m2 months ago

If you only need to check for the presence of an object without identifying it or checking for material: Go optical ;)
For example by getting some cheap optical mice and salvage their sensors.
Of course you can also try a simple photo resistor if you play in normal light conditions.
In either case you can detect the change and use electronics to create the output you want from there.
With conductive tape, fabric or similar you always have the problem of actually getting enough change (or weight) to make them work reliable.
As a really simple solution you could also make a shallow box and use plates on soft springs with micro switches to detect if something was placed on the area in question....

fourchu (author) 2 months ago

maybe conductive fabric ?

https://www.instructables.com/id/How-to-Work-With-Conductive-Fabric/