Prototypes for LED Applications

The prototype engineering group develops prototypes and models making UV LEDs usable in specific application fields.

UV-B module for plant growth lighting

This module allows the irradiation of a defined area with UV-B light of specific wavelength. UV-B LEDs offer a narrow emission spectrum, and their peak-wavelength can be tailored to ideally match the effective spectrum. This UV-B module can, for example, be used to optimize the biosynthesis of specific natural plant substances. It can additionally be supplemented with red and blue LEDs - their irradiation intensity can be adjusted indepently from each other. This setup including software controlled automated irradiation cycles ensures an optimum test procedure of LED lighting used in plant growth research.

UV-C module for fluid disinfection in flow

This module allows to disinfect low amounts of slowly flowing liquids by irradiation with UV-C LEDs. It is therefore particularly suited as point-of-use device for sterilizing, e.g., cell-carrier fluid in flow cytometry. The peak-wavelength can be tailored to obtain the most-effective germ-inactivation rate. Depending on the LED power, the quantity of flowing water to be disinfected is currently limited to 10-20 ml/min.

UV-C LED module for water disinfection in flow-through reactors

FBH has designed a rod-shaped module for water disinfection purposes using in-house developed 262 nm LEDs. This module aims at replacing conventional low-pressure mercury vapor lamps. UV LEDs score with higher lifetimes and are maintenance-free. Since they do not require toxic chemicals like mercury, they are environmentally friendly in addition – mercury lamps need to be disposed safely after a few 1,000 hours operation. Wavelength and emission characteristics can also be adjusted specifically to the desired application. FBH’s demonstrator utilizes 40 LEDs each delivering an optical output power of 1.7 mW; the medium irradiation intensity at a distance of around 2 cm is at approximately 2.0 W/m2. The geometry follows conventional flow-through water disinfection reactors, for example, for treatment of drinking or process water. This FBH setup is modularly expandable and can thus be adapted to various reactor sizes. Two LEDs form an assembly group with a constant current supply (max. 100 mA per LED) and a temperature termination for security reasons. Heat is dissipated via a heat pipe with attached fan.