Scientists have developed a substance that helps transform mechanical energy into electrical energy by combining baking soda and a derivative of starch. The method, which was created by researchers at Daegu Gyeongbuk Institute of Technology (DGIST) in collaboration with peers in Korea and India, is affordable and biocompatible and may be used to recharge low-energy electronics like watches and calculators. The details were published in the journal Advanced Functional Materials.
“Triboelectric nanogenerators harvest mechanical energy and convert it into an electric current,” explains DGIST robotics engineer Hoe Joon Kim.
“But many of the materials used in these devices are considered a biohazard and are not suitable for wearable applications. Our triboelectric nanogenerator incorporates cyclodextrin, a green material that is widely used for drug delivery in the human body, making it eco-friendly and hazard-free.”
A polysaccharide made from starch is called cyclodextrin. It was employed by the researchers to create a structure known as a metal-organic framework (MOF) by joining sodium ions together. In gas storage, catalysis, and sensing, MOFs create porous materials that are often used.
Kim and his group specifically used ultrasound on a solution of cyclodextrin and sodium bicarbonate in water. Trimesic acid was subsequently added, and a brief ultrasound session was repeated. The MOF is created as a result of the process, which takes place at room temperature and involves sodium ions connected by cyclodextrin bonds.
Triboelectric nanogenerators harvest mechanical energy and convert it into an electric current. But many of the materials used in these devices are considered a biohazard and are not suitable for wearable applications. Our triboelectric nanogenerator incorporates cyclodextrin, a green material that is widely used for drug delivery in the human body, making it eco-friendly and hazard-free.
Hoe Joon Kim
The MOF was included into a nanogenerator by covering a copper electrode with polyethylene terephthalate (PET), which serves as the base. A Teflon layer is positioned atop a second copper electrode that is adhered to a PET sheet in the opposite direction to the MOF layer.
When someone walks or runs, the two sides of the nanogenerator open and close in response. An electric current is created every time the MOF makes contact with the Teflon due to the exchange of electrons.
This process is called the triboelectric effect. The group put the apparatus to the test by fastening it to a shoe, a rucksack, a person’s knee, and their abdomen.
They discovered that it could generate mechanical energy from activities like jogging, bending, and even some common yoga poses. The system may power low-power devices like a calculator, a hydrometer, and a digital watch.
“Our MOF extends the list of triboelectric materials,” says Kim. He and his team plan to continue looking for biocompatible materials that can be used in wearable applications. They are also working on developing super capacitors that can store energy generated from triboelectric nanogenerators.
“Using the nanogenerator and super capacitor together, we believe we can develop next-generation energy systems for wearable electronics, biodevices and robots,” he says.
