After last day's chat on shoutbox, I decided to post a blog entry about making DIY resistive sensors... I tested many materials for making a resistive touch, pressure or bend sensor for robotic hand... best I could find was the antistatic black foam which came with my processor packages... some of these antistatic foams make very well pressure sensors. they are thin and changes resistance when pressed... useful for making fingertip sensors... you can sandwich this foam between two thin copper tape (don't use sticky ones because the adhesive is not conductive)... I prefer to sandwich all the layers inside a soft heat shrink tube... There is a firm called HollandShieldingComp. manufacturing conductive material and you can ask for a sample pack which they send you... I found many useful material from that pack... 

Another approach is to make conductive rubber from some silicon chaulk and starch, adding carbon powder which can be found from refills of laserprinter cartridges. There are many instructables on making conductive rubber on the net, like this one... the amount of added carbon powder defines the resistivity of rubber you made... less silicon, more carbon makes it harder but more conductive. the other way around it comes out very soft and flex, but less conductive... you can find the best mix for your needs by trial and error.

after making the sensor, It is very easy to read it with analog inputs of Arduino... connection is the standard pulldown unknown resistance reading procedure...  

GroG

10 years ago

Great Post Borsaci !

My experience has been to use different anti-static packing materials which came with electronics or ICs.  I found that they varied considerably in conductivity.  Most worked well as pressure sensors.

Here's one of my heros from LMR - Sir Gareth in an excellent video showing a construction of a simple stack of ic foam as touch sensor.