Bioprocess Engineering (Prof. Dr.-Ing. Clemens Posten)

Development of LED-based illumination units for photobiotechnology

All phototrophic processes require light as the energy source for photosynthesis. Therefore, photo-bioreactors employed for research of these processes (e.g. measurement of kinetic parameters, response to light/dark cycles and to different light colours) on a laboratory scale need highly controlled artificial illumination. Over the past few years there has been rapid development of more powerful LEDs with a wide range of spectral distribution. Application of LEDs in photo-biotechnology offers considerable advantages over the use of conventional lamps such as higher light intensity and flexibility for different reactor geometries. Light/dark cycles and dimming can be easily regulated by PC.
Advantages of LEDs:

- Lifetime of up to 100.000h
- Nearly no heat emission at the front side of the LED
- Light/dark cycles up to 200Hz and 2000 µE m2 s-1
- Homogenous light distribution