Leuven, Belgium: Building on last year’s rigid-surface development, INTEC reports that it’s produced the first functional optical links embedded in a flexible substrate. INTEC is IMEC’s associated laboratory at Ghent University. With this technique, it becomes possible to make foils that sense changes in pressure. These skin-like foils could be used in applications that have irregular or moving surfaces, such as robots, pliable machinery, or perhaps artificial skin.
To achieve these optical foils, INTEC thinned down gallium-arsenide (GaAs) photodectors and GaAs VCSELs (vertical-cavity surface-emitting lasers) to 30 microns. Then they’re embedded into a flexible foil of optical transparent material and optically coupled with embedded waveguides and out-of-plane micromirrors. The final structure shows good adhesion and flexible behavior.
IMEC, in turn, will employ this technology into array waveguide sensors and optical fiber sensors, both of which are currently being developed. It’s been shown that integrated optical interconnections are insensitive to EMI, highly sensitive, and rugged.
Optical sensing foils combine two burgeoning technologies—integrated optical interconnections and flexible, stretchable electronics. The goal is to create a flexible, stretchable skin-like foil sensitive to touch, pressure, or deformation. In fact, this is driving force behind the 7th Framework project PHOSFOS (Photonic Skins For Optical Sensing), which is a collaboration among a group of European research institutes that includes IMEC. PHOSFOS will develop photonic foils based on optical fiber sensors, and it's targeting applications ranging from monitoring the integrity of dams, bridges, etc., to monitoring of aircraft wings, to skin-like membranes that monitor respiration and cardiac activity in bed-ridden patients.
IMEC is an independent research center that focuses on nanoelectronics and nanotechnology.