Designing e-Static interactions
A triboelectric generator circuit is used as a template for designing and observing interactions between people and textiles with static electricity.
When charged up through continuous interaction, the difference in potential between the skin and electrostatic textile material, such as a winter jacket maintains till we touch a conductor such as door knob or metal surface. All the extra charges accumulated on the textile now get a path through our bodies to the door handle neutralising the difference in charges for the moment. This results in the tiny jolt of electrostatic shock. However, if we had been moving inside our winter jackets all along holding the metal object that is connected to the ground, the excited electrons would be flowing continuously through our bodies into the conductor without giving us a shock. This is a principle behind several anti-static measures implemented in clothing and home furnishings. It is also how a triboelectric generator works to safely harvest small amounts of electrical energy produced due to the electron flow.
The triboelectric circuit has two electrodes or conductive elements with one of them insulated with an electrostatic material. The two electrodes are connected to a rectifier circuit and an output, for e.g. a LED. When a person rubs against the electrostatic material while in contact with the open electrode, the electrostatic charges generated through the interaction flow safely through the body and into the circuit enabling the flow of electricity and lighting up the LED in short bursts.
In this setup, the person plays a crucial role in connecting and moving different kinds of materials and human skin is integral to the electrical setup that enables the circuit to work. In this way, the configuration of different materials and movements within a triboelectric circuit for generating meaningful electrical signals becomes an interaction design problem.
The triboelectric circuit could be shaped into textile substrates to support the generation and flow of electrostatic charges from our everyday interactions with textiles. Existing textile manufacturing techniques, such as weaving or tufting can be used to introduce conductive electrodes insulated with electrostatic materials. >>
The triboelectric circuit can be scaled up into an interior space with a distributed network of electrostatic and conductive materials to provoke electrostatic choreographies for engaging with static electricity. The interaction between the body and the electrostatic materials can transform an otherwise dormant interior into an electrically-active object. >>
High voltage but very little current is an aspect of static electricity that places a considerable constraint on how it can be electrically interpreted for e-Textile applications. However from an interaction design perspective this constraint presents an opportunity to consider a different treatment of time and material in interactions. The difficulty of directly using the power generated by the interactions to run bigger devices or components forces one to think in the long term- where not a single interaction but rather a series of them over a longer period of time would be recognised by the e-textile. >>