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Colloquia & Guest Speakers


Optofluidic Smart Glass for optically-configurable building envelopes and smart windows

Dr. Keith W. Goossen, University of Delaware

Monday, February 25, 2019
3:30 p.m.
Goergen 101

Keith Goossen


The talk will introduce a cost-efficient, high-performing smart glass system for windows, windshields, and building envelopes, including roofing whose reflection varies with the seasons for reduced building heating and cooling costs. This optofluidic smart glass system is based upon a reflective structure that switches from highly reflective to transmissive by introducing an index-matching fluid into a thin cavity of a panel designed with a solid retroreflecting structure.  The fluid greatly reduces facet reflection resulting in high transmission.  Inexpensive fluids have been developed that have precise index matching, low cost, and appear to have chemical stability.  While currently our panels are made with a 3D printer, we are working on panels using injection molding which should result in panel costs including the fluid of < $10/ft2.  Thus, it is projected that a m2panel with the pump may cost ~ $100, about 1/10 the cost of current smart glass technologies.  The issue of refractive clarity will be discussed and illustrated, which is that even though the panel has high transmission in the fluid state, a small refractive index mismatch results in multi-refraction of rays resulting in a distorted view of objects.  Photographs of panels with best matching will be shown, and hopefully some at different temperatures by the talk showing the effect of thermo-optic mismatch.


Keith W. Goossen (PhD Princeton 1988, Bell Labs ’88-2000, co-founder Aralight ’00-’02, University of Delaware Associate Professor ’02-’18, Professor ’18-), has spent most of his career working on devices to manipulate light. He is perhaps most well known for his work performing heterogeneous integration of GaAs quantum well modulators on silicon VLSI, including supplying such chips to researchers globally, which could be considered a precursor to Silicon Photonics. At University of Delaware his work includes MARS and quantum well modulators for retro-communication, integration of passive and active optical transponders in structural materials for non-pigtailed optical fiber strain sensors, 3-D packaging of spectral-spitting solar cells with efficiency ~ 40 %, the first demonstration of large format (512x512) heterogeneous III-V active devices on silicon VLSI for infrared scene projectors, and tailored-spectrum obscurant. In 2006 he established the Mid-Atlantic Industrial Assessment Center, a multi-grant Center that trains students and provides energy efficiency service to local industrial, governmental, and non-profit facilities through funded energy audits, about 300 to date, savings these facilities $millions/year and training about 50 students to date in energy systems. Dr. Goossen is a Senior Member of IEEE.

Location: Goergen 101

Refreshments will be served.