Let's Make Robots!

PolyMorph Workshop 2 - How to make a Servo controlled Finger or Scorpion Tail

Grasps things
  • Sensors / input devices:

Introducing the PolyMorph finger ...... or toe if you dare to use as locomotion

The idea is Inspired from Anthropomorpic finger

PolyMorph is a Flexible plastic when thin and is actually quite durable.

NonStream Video link :-

How to Make Finger (circa 35meg)

Scorpion Tail in Action (circa 4meg)

 (1 CUN)


Extra Ideas :- ScorpionTail /Ocotopus Tentacle :- same idea but more joints.




LMR Qoute "Remember 2010 is the year of colours, smiling and sound for robots. (Chips on acid)"



Colourful Pictures for Fritzl & LMR Crews around the World.

 But so far i have been unable to make a sound like an Octopus or Scorpion.......


















Optional Extras :- 

For measuring tactile pressure a small black square "Thingy" is needed..

In my video example i am using it as a "joint" feedback monitor... 

......... you will have to watch the video to find out what it is ......

Very High Resistance at rest typically >10 Tera Ω 

and very Low Resistance when compressed typically <1 Ω

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

That was great Gareth! Reminds me of a robot hand I made when I was an apprentice electrician. As for mounting the QTC it seems to me that shouldn't be too hard. The polymorph is very similar to hot melt glue.

I would use a soldering iron to melt a very small area where you want to mount it. strip back the end of your wire and press the bare end of the wire into the polymorph with the QTC so that the QTC and wire are pressed together. When the polymorph hardens it will hold them together. Another piece of wire can be mounted on the other side in a similar fashion.

By using a fine tip on your soldering iron, a thin groove can be formed in the polymorph to run the wires in. Once the wires have been pressed into the groove the molten poymorph that was displaced by the soldering iron tip can then be smoothed back over the wires thus embedding them in the finger. 

Can you tell me what Google won't? How did you come to know QTC? And where do you procure it? And is it worth investigating further, or is it way too expensive/unavailable?

Is it this? 


 I've never heard of MUTR before, has anybody used them? 

Nice find MrDan.

Yes that is the QTC (even down to the 10A)

That is a very good price compared to maplins

I can only find it in Maplins

Unfortunately its been discontinued.

I bought my last batch from a visit to the UK.

Its amazing stuff - and will easily survive 300ma (ie you can direct drive a motor with it) perhaps even more before it melts.

edit:- OMG just read it can survive 10A

I have only seen it in small squares - which is a pain because its not easy to mount.

One plus point is ...... its a little on the magnetic side !!!!!!

Nice walkthrough Gareth. The title photo makes me think of a scorpion's tail... perhaps this requires further investigation =)


I aimed at Octopus tentacle - but it came out Scopion Style - your subliminal message got the better of me.......

Before long you'll have a bot that can do this...

...and then we'll all be in trouble =)