A temperature and weight sensor made on paper
Can charge itself, could be useful in wearable devices.
doi:10.1038/nindia.2019.81 Published online 26 June 2019
Researchers have invented a sensitive sensor that can convert temperature, human motions and mobile vibrations into electrical signals1. As the sensor is self-charging, it can function even in the absence of electricity.
Such a sensor could be useful in wearable devices, which usually run on batteries that need to be recharged. In remote locations where electricity is not available, such devices run out of power.
In search of a self-charging device that can run even in the absence of electricity, scientists from the National Institute of Technology in Durgapur, Jadavpur University in Kolkata and the Institute of Nano Science and Technology in Mohali, all in India, fabricated the self-powering sensor by smearing a mix of non-toxic glues on a normal printer paper.
The researchers, led by Pathik Kumbhakar, tested its efficiency in converting mechanical energy into electrical signals.
When various compressive pressures were applied to the device, it generated output voltages that increased with increasing pressures. The device was also found to be extremely sensitive to temperature and weight.
Increasing the temperature gradually from 20 to 50 degree Celsius increased the device’s output voltage. By reading out the voltage, it is possible to measure the temperature. This suggests that the device could work as a temperature sensor.
Given its sensitivity to pressure, the device was then exposed to different weights of men and women, ranging from 50 to 72 kilograms.
The output voltage increased linearly with increasing weight. By knowing the voltage, it is possible to measure the unknown weight of any person lying below 72kg, indicating that the device could also be used as a weight sensor.
1. Karmakar, S. et al. Development of flexible self-charging triboelectric power cell on paper for temperature and weight sensing. Nano. Energy. doi:10.1016/j.nanoen.2019.06.027