Author(s) : Martin De Bie
The idea is to create a non-woven homemade piezoresistive material. By using the technique of making cotton paper mixed with graphite powder, i manage to create a piezo resistive material which can easily replace expensive material like Eeonyx. This process is the continuity of an experimentation made with students (Céleste Teikiteetini and Jules Lobgeois) during a workshop that i lead.
To show the capabilities of this material, i integrate it into a simple circuit with led where it would play the role of simple pressure sensor for the swatchbook exchange of the summer camp eTextile 2016.
Ref/inspirations :
Pulp-Based Computing by Marcelo Coelho
http://www.cmarcelo.com/pulp-based-computing/
1- Material
– water
– cotton
– fabric
– paper
– graphite powder
![](https://www.martindebie.com/wp-content/uploads/2020/04/1-material_27665619992_o-768x1024.jpg)
2- prepare paper pulp
Cut cotton, paper and fabric in small piece and put it inside a bowl of water. Leave it like this during 48h at least.
![](https://www.martindebie.com/wp-content/uploads/2020/04/2-make-paper-pulp_27487896610_o-1024x768.jpg)
3- Make paper pulp
Use a blender to mix your paste into something homogeneous.
![](https://www.martindebie.com/wp-content/uploads/2020/04/3-make-paper-pulp_27766188355_o-768x1024.jpg)
4– Add graphite
Add into your paste graphite, the proportion depends on your tests. In my case, i put 4 big soup spoon for 800g of paste.
![](https://www.martindebie.com/wp-content/uploads/2020/04/4-add-graphite_27766187845_o-768x1024.jpg)
Mix it together with a spoon until you get a very black paste.
![](https://www.martindebie.com/wp-content/uploads/2020/04/5-add-graphite_27732064256_o-768x1024.jpg)
5- Prepare your graphite pulp
Put your mix inside a big container and add a lot of water. Your mix need to be dilute to make your paper.
I use a frame that i’ve build with regular tulle attached to the wood.
![](https://www.martindebie.com/wp-content/uploads/2020/04/6-prepare-your-graphite-pulp_27766206155_o-1024x768.jpg)
6- Make a sheet of paper
Dip your frame and take it out from the water quickly to catch pulp to create your sheet.
Apply your sheet on a piece of felt to absorb the water and let it dry.
![](https://www.martindebie.com/wp-content/uploads/2020/04/7-make-a-sheet-of-paper_27691803931_o-1-1024x768.jpg)
You can try to add together different layers of paper to increase the thickness of the sheet and the resilience of the matter.
![](https://www.martindebie.com/wp-content/uploads/2020/04/33743367811_d442a0388e_o-768x1024.jpg)