A working transparent speaker has been produced by a research team at Harvard, that uses ions, rather than electrons, to carry the electrical charge.
The transparent speaker, created at Harvard University, is made from two layers of polyacrylamide gel swollen with salt water, which act as electrolytes, sandwiching a thin rubber membrane that vibrates as a high-voltage signal is run across its surface. However, this is not any ordinary electronic device, as the electrical charge is carried by ions, not electrons.
This bendable, transparent speaker could be a step in the direction of wearable tech that blends seamlessly with our bodies. What do ionic conductors have that other electronic systems don’t? They can be stretched to many times their normal area without an increase in resistivity, for one. This resistivity is a problem common in stretchable electronic devices. In addition, they can be transparent, which makes them well-suited for optical applications. Thirdly, the gels used as electrolytes are biocompatible, so it would be relatively easy to create ionic devices such as artificial muscles or skin.
Source: igyaan.inAdded: 4 September 2013