Build Efficient Force and Position Sensing resistors to detect touch, presence, pressure or displacement over and along a surface
Force Sensing Resistors
Volume conductive papers are practical and sustainable ressources for building quickly small Force Sensing Resistors, but other electrically resistive materials exist.
Volume conductive papers have a relatively homogeneous electrical conductivity ranging between 1kOhms/Square and 100kOhms/Square. These materials roughness, porosity and shape-memory are especially usefull when used as piezoresistive materials under various kinds of design.
Force Sensing Tiles
Conductive papers enable the production of a large variety of electronic components such as touch sensors and finger size force sensor.
For very small (narrow) sensors only, this design can be produced and tested under a minute and 4 steps:
Step 1) Sizing and cutting Step 2) Mount & Test Step 3) Conditionning Step 4) How to use it?
Take a band of resistive paper of around 1 cm width and twice the length of your sensor's width.
Paste a band of copper tape 100K paper.
Check the resources specs for more information before setting up connectors.
Linear Touch Resistve Potentiometers
Electrically Resistive Papers provide uniform and scalable volumes to build up easilly linear and .
Check the various examples of sensors designs to be produced with conductive papers, produce your own and test its resulting conductivity.
Linear One Touch Resistve Arrays
Large Linear Touch potentiometers can be designed to quickly build 2D position surfaces of any size. Arrays of linear Touch Potentiometers are even a better stratefy.
These One-touch interface can be combined with a large Force Sensing Resistor to detect as Well the force applied.
Refined Signal Analysis can also enable experienced users to detect Low level Multi-Touch Events and Gestures Tracking
Multi-Touch Resistve Arrays
Both Force sensing Resistors and Linear Touch potentiometers can be designed as an Array of multiple rows and lines connected to an acquisition board (e.g. Arduino) using simple (Ghost) Multiplex Implementation Scheme and a few variatio of complimentarry elements (e.g. transistors, Leds and resistors).
Check the various examples of Contact Sensing Arrays o be produced with PapierLogik Development Kits..
Other Contact Sensing Variations
The previous sensors design described above can be combined together: they are thin and can be for instance mounted vertically and along flat and curved shapes as long as the support provides sufficient hard contact surface. You just need to decide on the appropriate shape, size and connexion method for your sensor.
Check the various examples of alternate designs to be produced with conductive papers.
Other Paper-Based Sensors
Paper-based resources for DIY electronics can also be used to build other types of resistve sensors such as bend or traction sensors, thermistor or humidity sensors. They can also be used as many other electronic components that can get as recyclable as the contact sensing resistors presented above.
Check the various examples of sensors designs to be produced with conductive papers.