This tutorial will show you how you can quickly make a DIY version of GPutty (Graphene Putty) which is a super pressure -sensitive polymer you can use as a robust sensor for a variety of projects and interfaces. This sensor is so multi-purpose and sensitive it could do things like monitor your breathing and pulse just by sitting on your neck. This is a knock-off version (I'll call it "Goophene," -get it?) of the "GPutty" idea made by Coleman et al at Trinity College (https://www.npr.org/sections/health-shots/2016/12/...)
This DIY type seems nearly as sensitive as the lab-made stuff these guys describe (i tried re-creating the examples they gave). I've already succeeded in hooking it up to a microcontroller and sensing:
- Loud sounds
- light touches with a napkin
- ultra light touches with .012" monofilament
- Typing on the table nearby
- June-bugs walking around
- ANGRY ants (but not calm ants- more on this later)
- Inertial gestures (like sticking it on your finger an wagging it around)
So check out this how-to, and join me in playing with this new cool substance and figuring out fun new types of interfaces to make with it! I'm also a professor, and if anyone wants to write a paper with me to send to something like TEI (Tangible, Embedded and Embodied Interaction), Ubicomp, or CHI (Computer Human Interaction), types of places might be interested in fun new interactions we can design with this!
It can still be a bit quirky and unpredictable, but we are getting there! Maybe you will be able to help me improve this!
Here's a quick example of me playing with it with some hairs in it.
- Graphene Powder (not Graphite, not Graphene Oxide, you need actual graphene)
- you need about 2 times as much graphene (by volume) as silly putty
- Graphene is pricey, but a little bit goes a long way with these sensors
- Different places have different prices that really vary, shop around!
- Silly putty (can buy it in those little eggs, or even giant eggs!
- Acetone (i used nail polish remover)
- Silicone Oil
- You can find this as a silicone spray at hardware stores (make sure it's silicone spray) https://www.wd40specialist.com/products/silicone-...
- or there's certain stores that sell silicone oil for body parts like this one that the military in switzerland seems to use. These work alright toohttps://www.amazon.com/SWISS-NAVY-Premium-Silicon...
All done, I'd say a single little blob sensor doesn't cost more than 2-3$ of raw materials.
- Safety Gloves
- Safety Goggles
- Stirring Sticks
- Aluminum foil to lay down (it's gonna get messy)
Our Recipe (cups, sticks, goo, nail polish remover, putty)
In contrast our recipe is a bit quicker and easier to do at home! It will take you about an afternoon. The key is making use of commercially available silly putty, and finding out that acetone (readily available as nail polish remover) will dissolve both the putty and the graphene together pretty well before evaporating away. Here's the quick recipe
- In one cup, Mix a glob of silly putty with acetone. Stir it up for about 10 minutes until it gets nice and gooey. Let sit for maybe 15 more minutes.Shake it around to help break it up
- In another cup stir in some graphene powder to acetone. (use about 2 times as much Graphene (by volume) as your silly putty). Shake it up good!
- Scoop out your silly putty goo, and add it to the acetone cup full of graphene.
- Shake up this cup really vigorously for like 10 minutes (Advanced: you can also set it on a large vibrating wand and let it mix for like 20 minutes)
- After it's gotten shaken up really good, it will look like a clear liquid with tiny dots suspended in it.
- Open up your cup in a well ventilated area, and let the acetone evaporate off
- Give a brief spritz of silicone oil
- mix up the dried up goo + oil until it forms a nice putty-like substance.
Check your resistance , if it's mixed up good, a little...Read more »