Small responsive interrupters or force sensors can quickly be built using conductive papers, connectors and wires.
Follow the guide steps below to build you own sensors and improve you skills.
Larger sensors and sensitive surfaces can also be produced with co;plimentary design strategies: follow this specification guide when building large sensors or sensors with specific sensitive areas.
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 1 kOhms/Square and 100 kOhms/Square. These materials roughness, porosity and shape-memory are especially usefull when used as piezoresistive materials under various kinds of design.
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.
Step 2) Mount & Test
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
Step 3) Conditionning
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?
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.