Back to top

Building DIY Small Thin Paper-based Force Sensing Resistors

Undefined

Small responsive force sensors can quickly be built using conductive papers, connectors and wires. Follow this guide steps to improve you technics

Resources

Conductive Paper 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.

Design

Conductive Paper 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.

Step 1) Sizing and cutting

Connectors and wiring can be made with many types of materials from conductive paper clips to a variety of metal foils, tapes or else conductive textiles. Working with conductive paper, tin-plated copper tape is the perfect materials for designing and fixing connecting pads and tails and even small circuits.

Check the various examples of sensors designs to be produced with conductive papers, produce your own and test its resulting conductivity.

Step 2) Mount & Test

Conductive papers

The resulting resistance can be reduced by reducing the element size depending on the chosen design. It can be increased by extending the size of the components

Using an insulating paper support can enable to produce connecting tails using metal tape. Various alternatives exist for connecting and wiring the component

Once the component is operational it should be at least insulated and reinforced using a paper-based adhesive. For higher shear resistance (i.e. finger touch vs foot-pressure) and lower moisture variations (e.g. used inside vs outside) and short vs long life-time), Thermoplastic adhesives will provide more durable solutions

Step 3) Conditionning

Conductive papers

The resulting resistance can be reduced by reducing the element size depending on the chosen design. It can be increased by extending the size of the components

Using an insulating paper support can enable to produce connecting tails using metal tape. Various alternatives exist for connecting and wiring the component

Once the component is operational it should be at least insulated and reinforced using a paper-based adhesive. For higher shear resistance (i.e. finger touch vs foot-pressure) and lower moisture variations (e.g. used inside vs outside) and short vs long life-time), Thermoplastic adhesives will provide more durable solutions

Step 4) How to use it?

Conductive papers

Paper-based components should only be used for low power electronics (e.g. 5Watts), and should never be left plugged to a power source when not used, as for any electronic device for security reasons and energy savings.
Check the various examples of sensors designs to be produced with conductive papers.