NTT Research has created a circuit and a battery connected by wires made of carbon tubes as opposed to copper. Copper is both rare and harmful to the environment in large quantities, whereas this battery is completely recyclable and uses chemicals found in fertilizer to power the transistor. The resulting transistors are very low-frequency devices that don’t even achieve a kilohertz of performance. (Chip performance is measured by frequency, with today’s high-performing chips reaching frequencies of multiple gigahertz.) These transistors can’t even generate enough performance to send out a radio signal. Which, by the way, is the next goal of the research team. NTT envisions a “greener” IoT sensor – Stacey on IoT | Internet of Things news and analysis