Many people think that shadows are just useless. But, recently, scientists proved that shadows and light could be teamed up to produce an electric current. A material scientist, Swee Ching Tan, from the National University of Singapore, exploited the contrast between shadow and bright spots, along with his team, to generate an electric current that could be used to power a small gadget.
The scientists said that energy could be harvested anywhere on Earth; not just open spaces. Therefore, they created a new device to team up shadows and light and produce power for small electronics. They called it, “shadow-effect energy generator”.
Device to Produce Electricity Using Shadows
They placed a super-thin coating of gold on silicon which is a typical solar cell material. Just like a solar cell, when light shines on silicon, it energizes its electrons. When a part of the shadow-effect energy generator lies in shadow, it produces an electric current due to the gold layer. This happens because the excited electrons jump from the silicon to the gold.
While part of the device is shaded, the voltage of the illuminated silicon increases relative to the dark area, and the electrons in the device flow from high voltage to low voltage. When the electrons are sent through an external circuit; they create a current that is enough to power a gadget.
The scientists used eight generators to run an electronic watch under low light. They stated that the new device could also serve as a sensor. If a remote-controlled car passes by the device, its shadow would fall on the generator and producing electricity to light up an LED.
The scientists also observed that the greater the contrast between dark and light, the generator would produce more energy, Therefore, they have already started working to enhance the performance of the device by following solar cells’ strategies.
If the light on the device is increased, it would absorb more light and exploit shadows better. Moreover, it’s possible that it would produce energy in the shadowy spots in a solar array, between skyscrapers or even indoors.