The seaweed-like proof-of-concept generators were ~40 x 80mm, and attached at one end to somethign solid while currents in the water wafted the free end.
They were made by coated two strips of different polymers with conductive ink and sealing them back to back with an air gap, maintained by spongy material (diagram right).
“As the TENGs were moved in water, they bent back and forth, generating electricity,” according to the Americal Chemical Society, which has published the project’s findings. “When the researchers put the TENGs in pressures that typically exists at a 30 foot water depth, they found that the devices still generated a current.” This was at 100kPa.
Held near the surface in a wave tank “the researchers demonstrated that multiple TENGs could be used as a mini underwater power station, supplying energy for 30 LEDs,” said ASC.
Triboelectricity is genrated by different surfaces in rubbing contact – a balloon and a wooly jumper, for example.
In the project, Dalian Maritime University worked with the Georgia Institute of Technology, Max Planck Institute for Intelligent Systems, Sun Yat-sen University and the Chinese Academy of Sciences.
‘Flexible seaweed-like triboelectric nanogenerator as a wave energy harvester powering marine Internet of things’, published in ACS Nano, describes the work.
There is an assoicated video