A thermoelectric wearable radiation harvester is a device that converts ambient radiation, such as heat or light, into usable electrical energy through the principle of thermoelectric effect. The device is typically integrated into a wearable form factor, such as clothing or accessories, allowing it to harvest energy from the wearer's surroundings and convert it into electricity that can be used to power small electronic devices or charge batteries.
The working principle of a thermoelectric wearable radiation harvester involves two main concepts: the Seebeck effect and the Peltier effect.
Seebeck Effect: The Seebeck effect is the phenomenon where a temperature difference between two different materials generates a voltage difference, creating an electric current. In the case of a thermoelectric harvester, two different types of materials with distinct thermoelectric properties are used. One material has a higher electron density (n-type) and the other has a lower electron density (p-type). When one side of the device is exposed to a heat source (such as the wearer's body heat), and the other side is exposed to a cooler environment, a temperature gradient is established across the device.
Peltier Effect: The Peltier effect is the reverse of the Seebeck effect. When an electric current flows through a junction between two different materials, it causes a temperature difference across the junction. In a thermoelectric harvester, the temperature difference created by the Seebeck effect also leads to a flow of electric current due to the Peltier effect. This combination of effects results in a continuous conversion of heat energy into electrical energy.
The thermoelectric materials used in the wearable radiation harvester are carefully chosen based on their thermoelectric properties, such as high thermoelectric efficiency (high Seebeck coefficient), low thermal conductivity, and good electrical conductivity. This allows the device to efficiently convert the temperature gradient between the wearer's body and the surrounding environment into a voltage difference and subsequently into electrical power.
The generated electrical energy can be used to power various low-power wearable electronics, such as sensors, communication devices, or even charge small batteries. These thermoelectric wearable radiation harvesters have the potential to extend the operational lifetime of wearable devices or reduce the need for frequent battery replacements by harnessing ambient energy from the wearer's environment.