Alessio Buzzin

Electro-optical detector for lab-on-chip applications

This paper presents the integration on the same glass substrate of an amorphous silicon photodiode and a diffused waveguide, to achieve an integrated evanescent waveguide sensor. Simulations performed with COMSOL Multiphysics show that the coupling efficiency between the waveguide and the photosensor is strongly affected by the presence of the passivation layer, and by thickness and refractive index of the transparent electrode of the photodiode. A first prototype has been fabricated using standard microelectronics techniques in a 6-masks process fiow. Electro-optical characterization, performed measuring the diode photocurrent with and without lighting the waveguide, shows the effectiveness of the optical coupling between diode and waveguide, and suggest its use for on-chip detection in lab-on-chip applications.

Design of an Evanescent Waveguide Sensor Based on a-Si:H Photodiodes for Lab-on-Chip Applications

Here we present the design of an amorphous silicon photodetector integrated with an ion-exchanged waveguide on the same glass substrate in order to obtain an evanescent waveguide sensor for on-chip biomolecular recognition in Lab-on-Chip applications. We studied the behaviour of a monochromatic light in a channel waveguide and its coupling into the thin-film sensor, using COMSOL Multiphysics. Simulations show that the presence of the photodiode’s insulation layer and transparent electrode strongly affects the coupling efficiency between the waveguide and the sensor.

Evanescent Waveguide Sensor for On-Chip Biomolecular Detection

This work presents analysis and development of an evanescent waveguide sensor system, which integrates an amorphous silicon photodiode and a glass-diffused waveguide. Design of the system includes a study of thickness and refractive index of the transparent electrode of the diode, which are crucial parameters for the optimization of the optical coupling between the waveguide and the photodetector. Preliminary electro-optical measurements on the fabricated device show excellent system performances, and suggest its use for on-chip detection in lab-on-chip applications.

Integrated System Based on Thin Film Technologies for Cell-Based Bioluminescence Assays

This work presents a miniaturized lab-on-chip system suitable for monitoring the activity of living cells through the on-chip detection of their bioluminescence emission. The system integrates amorphous silicon diodes, acting as temperature and light sensors, and indium tin oxide film, acting as heater, on a single glass substrate. During its operation, the glass is thermally and optically coupled to the investigated cells and electrically connected to an electronic board, which controls the lab-on-chip temperature and monitors the sensor photocurrents. The proposed lab-on-chip is particularly attractive for the development of portable cell-based biosensors useful for biological activity monitoring as well as for cell cytotoxicity evaluation.

Development of a NEMS-Technology Based Nano Gripper

This paper presents the first prototype of a new concept nanogripper whose overall size has been reduced as much as permitted by a new fabrication process based on Nano Technology. The jaws lumen size is adequate to the mechanical manipulation of microorganisms colonies.