Organic electrochemical transistor, cotton substrate, demonstrating a simple LED lighting operation. (via Cornell University)
The cotton substrate based organic electrochemical transistor and the organic field-effect transistor were created for two purposes, to be flexible and comfortable to wear. Is this a better solution to flextronics?
Cotton is not a good conductor. However, the researchers at Cornell University lead by Professor Juan Hinestroza changed this by applying a layer of gold nanoparticles within a coating of a semiconducting conducting polymer acting as the gate. Either ends of the strand of cotton are two electrodes made from a different conductive paint. Varying the voltage at the gate controls the current flow between the electrodes. The switch function of the transistor comes from making the strand conductive versus resistive.
The thread segments can be connected, via knotting the threads together, to form more complex systems. Hinestroza elaborates, "Perhaps one day we can even build computers out of cotton fibers in a similar way as khipus -- a recording device based on knots and used by the Inca empire in Peru." However, the current transistor is significantly slower switching compared to traditional silicon. However, it is a great first step. Keep in mind, every innovation starts from a humble early form.
Hinestroza stated that, "The layers were so thin that the flexibility of the cotton fibers was preserved." The longevity of the transistor submitted to repeated flexing was not covered in the research team's publication in the journal Organic Electronics. Cornell University is joined in this effort along with the University of Cagliari, University of Bologna, and the Ecole Nationale Supérieure des Mines de Saint-Étienne in France.
The envisioned application for the tech will come in clothing sensors and wearable medtronics. I think the technology would explode in popularity with simple .