Lifetime Imaging Sensor

Imaging and functional identification of (bio)molecular compounds by fluorescence on a single molecule level has found numerous applications in life- and material sciences. Many of interesting molecules and compounds – transition metal ions, highly conjugated organic compounds, and (parts of) biological macromolecules such as DNA and proteins – are naturally fluorescent in the near and middle UV range (~250-350 nm), so they can be imaged and identified without the need for labels. Current measurement and analysis methods enable us to identify and quantify only a small number of molecular species at a time, and only few of them work well in the UV. Single photon avalanche photo-diodes (SPAD) based array sensors allow for the measurement of photon arrival times, which makes them directly useable in lifetime experiments.

Our goal is to extend classical Fluorescence lifetime imaging microscopy (FLIM) into a multidimensional microscope. This microscope images not only the three spatial coordinates but also molecular lifetime, emission wavelength and molecular anisotropy. With such a ‘6D’ microscope we can achieve molecular specificity and quantify the relative concentrations of a large number of different molecular species at the same time.

In our presentation, we will approach the multidimensional imaging problem from a dynamic system identification point of view, and discuss how results from the field of systems theory may be exploited to develop computationally efficient algorithms and to further optimize the observation. These algorithms may be implemented in low complexity hardware, e.g., directly on chip, where the signal from each detector or group of neighboring detectors is processed by one single low-complexity processor. This will enable to develop a small, self-contained sensor unit with numerous applications in environmental sensing or as a contamination and safety detector.

CV Rufus Fraanje
Rufus Fraanje received his MSc. degree in electrical engineering from Delft University of Technology in 1999, and his Ph.D. degree from the University of Twente, Enschede, in 2004 for his thesis on fast and robust algorithms for noise and vibration control. After his PhD he has held positions at the Delft Center for Systems and Control (DCSC) from the Delft University of Technology and TNO Science and Industry. Currently he is affiliated at DCSC, where he is doing research on the control of optical systems. He was a visiting researcher with INRIA, Rennes, the Institute of Sound and Vibration Research (ISVR), Southampton, and the Adaptive Systems Lab, University of California, Los Angeles. His research interests are in the modeling and prediction of dynamical optical distortions and computationally efficient control for large scale (adaptive) optical systems with application to large scale telescopes, lithography systems and microscopy.