In this paper we report an optofluidic window shelter system that can be used for natural daylighting in buildings. The implementation of the optofluidic window shelter is based on electrowetting-on-dielectric (EWOD). The EWOD effect controls the contact angle between an electrolyte and a dielectric surface through the application of an electric potential difference between them. With two immiscible fluids (oil and water) in a transparent cuvette and with a high-reflectivity membrane film suspended between the fluid-fluid meniscus, we can actively control the contact angles along the fluid-fluid-solid tri-junction lines and hence the orientation of the membrane reflector via EWOD. As-formed dynamic reflector (heliostat) can be used for adaptive sunlight tracking and steering via reflection. Without any mechanical moving parts, this EWOD-tuned liquid prism allows the optofluidic heliostat to adaptively track both the daily and seasonal changes of the Sun’s orbit, i.e., dual-axis tracking, while steering sunlight into buildings for natural daylighting.
© 2016 Optical Society of AmericaPDF Article