MEMS smart glass for personalized lighting and energy management in buildings: working principles, characterization, active light steering, thermal management, energy saving considering different locations on earth, comparison of different smart glass technologies

A detailed quantitative overview on different micro-electro-mechanical systems (MEMS) smart glass technologies and smart glass technologies in general is given. Next, our MEMS smart glass is focused. This technology based on millions of miniaturized, tiltable, planar mirrors. Installed in windows or building facades, it allows personalized daylight steering as well as thermal and energy management in buildings via electrostatic actuation, strongly supports health and has a large potential for reducing CO2 emissions and energy consumption of buildings, noticeably. Various results of experimental characterizations and reliability studies are summarized. Simulations of light steering are reported for different use cases involving tailored variable tilt angles of the mirrors. Ray tracing is used to visualize light steering and distribution in a model room, showing that our MEMS smart glass can generate high illuminance where necessary in workspaces. Finally, simulations of energy savings are presented using hourly resolved real weather data over up to years, varying cloud coverage, daytime and seasonal varying irradiance via varying sun orbit, respective geo coordinates of different locations, energy price and others. Simulation results are depicted for four German and two international cities, varying in latitude and elevation. Huge energy saving potential of our MEMS smart glass and amortization of investment in MEMS smart glass within less than five years in the best case is reported compared to conventional window blind systems.