HomeProjectsSustainable Development and Green TechnologiesSelf-Powered Electrowetting Optical Switch Driven by a Triboelectric Nanogenerator for Wireless Sensing

Self-Powered Electrowetting Optical Switch Driven by a Triboelectric Nanogenerator for Wireless Sensing

Project Quick Facts

Principal Investigator

  • Prof. ZI Yunlong

    Department of Mechanical and Automation Engineering

  • Funding

    Research Grants Council of Hong Kong, and
    Shun Hing Institute of Advanced Engineering

The Internet of Things is widely applied in our daily live, such as smart sensing and recognition technologies, which contains thousands of sensors. Replacement of batteries for sensors is a difficult task and disposal of batteries may contaminate soil and water. By combining freestanding sliding mode triboelectric nanogenerator (FS-TENG) and electrically tunable liquid lens (ETULL) made of environmentally friendly materials, we develop a self-powered electrowetting optical switch (EOS) for wireless sensing networks.

Switching mechanism of the EOS, where the mechanical-electrical-optical signal conversion occurs. (a) EOS without mechanical motion. (b) EOS with mechanical motion loaded.
(a) Schematic diagram of the wireless sensing system. (b) Photograph of the wireless sensing system when no mechanical motion is loaded. (c) Photograph of wireless sensing system when the mechanical motion is loaded.

Uniqueness and Competitive Advantages:

  • Low cost, environmentally friendly
  • ETULL was fabricated by conducting fluid, insulating oil, transparent cylindrical spacer and indium tin oxide (ITO) electrodes
  • Switch controlled by voltage generated by the FS-TENG: light propagation through the ETULL; and light diverging by the concave lens due to electrowetting effect upon applying a voltage on the ETULL
  • Our design can detect both initiation and termination of mechanical motions, while most of the current mechanical sensors can only monitor motion initiation
  • Potential applications for environmental monitoring, building and infrastructure monitoring, wireless human machine interface, etc.

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