Imagine your gloves and shoes as an energy source, powering wearables, sensors, or smartwatches.That is the promise of triboelectricity and the new of TENGThat is, triboelectric nanogeneratorRenewable energies such as wind and solar power are becoming increasingly important in the energy mix. Still, other, lesser-known energies can also play a role, such as large-scale ones such as tidal and wave energies, and those found in the home environment such as triboelectricity. The triboelectric effect is nothing more than what is known as static electricity. The difference is that the latest research is discovering new ways to harness it.Incorporating it into textile fibers and floors can turn almost unsuspecting objects into clean power sources.
Applications of triboelectric effect
- Floor with triboelectric layer connected to IoT devices
- Smart clothing sensors to measure vital signs
- Shoes that can monitor physical activity
- Autonomous sensors as forest fire detectors
- tactile sensor
- dust and particle sensor
- LED power supply
How do triboelectric nanogenerators work?
Usually, the triboelectric effect is caused by friction between two surfaces, one donating electrons to the other. This is what sometimes happens when you comb your hair or take off your sweater. Triboelectric nanogenerators, first theoretically proposed in the early 2010s, utilize this principle to power miniature sensors. Basic TENG contains four layers. The top emits electrons, the middle traps them, and the bottom collects them. All three are covered with another layer that acts as a battery that stores the generated current that needs to be converted from alternating current (AC) to direct current (DC).
Specific materials such as lipids and nylons are used to optimize the functionality of the layer that emits electrons from TENG. However, it is the shape that greatly affects its efficiency. In other words, this principle is transferred to the nanoscale when, on large scales, roughness contributes to enhanced friction and electron emission. The latest generation of his TENG uses microstructures to generate more power. This is because these microscopic undulations increase the contact area exponentially. Subsequently, the triboelectric layer relief undergoes various treatments such as exposure to a negatively ionized air stream and plasma treatment to further increase its electrical capacity.
Friction is not the only way to use triboelectric potential. For example, a triboelectric film can generate an electric current under the influence of raindrops.
Triboelectricity of the sensor
The currents produced by such devices are very weak and mostly measured in milliwatts. However, this amount of energy is enough to power LEDs and devices embedded in smart clothing such as shoes and T-shirts. Furthermore, triboelectric systems do not necessarily have to be used to generate electricity to power other devices. The fact that they are actuated by friction or mechanical pressure makes them ideal candidates for sensors. For example, artificial skin can record your touch thanks to its triboelectric layer. Also, when you twist or stretch it, an electric current is generated, and you can monitor the movement of the joint.
TENG is an intricately designed device, but it has limitless applications for use in wearables or integrated into autonomous sensors that can operate in different situations such as homes, forests, and oceans.
sauce: Nature, the forefront of mechanical engineering
photograph: Georgia Tech
