ABSTRACT
This paper reports an optical strain sensor that integrates a self-powered mechanoluminescent (ML) elastic fiber with a flexible circuit. The inclusion of an alumina nanoparticle as the additive results in seven-fold enhancement of ML intensity while maintaining flexibility of 120% strain. The sensor facilitates the detection of strain and stretching speed. It attains a sensitivity of 0.0022â lx/(1% strain) and a resolution of 0.2% strain, respectively. We have successfully applied it to detect bending motions of the finger, wrist, and elbow. This wearable strain sensor holds promise for diverse applications in wearable technology.
ABSTRACT
Optofluidics seamlessly combines optics and microfluidics together to construct novel devices for microsystems, providing flexible reconfigurability and high compatibility. By taking advantage of mature electronic fabrication techniques and flexible regulation of microfluidics, electrically actuated optofluidics has achieved fantastic optical functions. Generally, the optical function is achieved by electrically modulating the interfaces or movements of microdroplets inside a small chamber. The high refractive index difference (~0.5) at the interfaces between liquid/air or liquid/liquid makes unprecedented optical tunability a reality. They are suitable for optical imaging devices, such as microscope and portable electronic. This paper will review the working principle and recent development of electrical optofluidic devices by electrowetting and dielectrophoresis, including optical lens/microscope, beam steering and in-plane light manipulation. Some methods to improve the lens performance are reviewed. In addition, the applications of electrical microfluidics are also discussed. In order to stimulate the development of electrically controlled liquid lens, two novel designs derived from electrowetting and dielectrophoresis are introduced in this paper.