Ricerc@Sapienza

This paper presents the development of a multi-hinge, multi-DoF (Degrees of Freedom) nanogripper actuated by means of rotary comb drives and equipped with CSFH (Conjugate Surface Flexure Hinges), with the goal of performing complex in-plane movements at the nanoscale. The design approach, the simulation and a specifically conceived single-mask fabrication process

An optoelectronic, integrated system-on-glass for on-chip detection of biomolecules is here presented. The system’s working principle is based on the interaction, detected by a hydrogenated amorphous silicon photosensor, between a monochromatic light travelling in a SU-8 polymer optical waveguide and the biological solution under analysis. Optical simulations of the waveguide coupling to the thin-film photodiode with a specific design were carried out.

This work investigates the influence of blue light on cell culture medium that is crucial for developing a biosensor for tumor cells. To this aim, the cell culture medium, DMEM and Trypsin, and 50% solution of DMEM and Trypsin were posted on the surface of amorphous silicon photodiodes and the variation of their photocurrent as a function of time was recorded. Results show, dependently on DMEM and Trypsin concentration, a photocurrent degradation and its unexpected increase after the expected influence of the Steabler-Wronski effect.

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

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.

This work presents a thin film device, combining, on the same glass substrate, photosensors and long-pass interferential filter to achieve a compact and efficient sensor for biomolecule detection. The photosensors are amorphous silicon stacked structures, while the interferential filter is fabricated alternating layers of silicon dioxide and titanium dioxide, directly grown over the photosensors. The system has been optimized to effectively detect the natural fluorescence of Ochratoxin A, a highly toxic mycotoxin present in different food commodities.

This paper presents the fabrication and testing of a lab-on-chip system suitable for treatment of DNA. It includes two main modules: a system-on-glass (SoG) and a disposable microfuidic chip. The SoG integrates, on the same glass substrate, thin film metal heaters and amorphous silicon temperature sensors to achieve a uniform temperature distribution (within 1°C) in the heated area. Two polydimethylsiloxane microfluidic chips have been developed: a PCR-Chip for DNA amplification and a dsDNA-Chip for separation and selective isolation of a ssDNA from a dsDNA.

In this paper, we report on the design, fabrication and characterization of a low cost, portable detection system able to quantify, in a rapid and reliable way, the contamination level of Ochratoxin A (OTA) in wine and beer. The operating principle is the real time monitoring of the natural fluorescence of OTA molecules during a chromatographic run on a Thin Layer Chromatographic plate. The fluorescence is detected by an array of amorphous silicon photosensors whose photocurrents are directly proportional to the amount of OTA molecules present in the sample under analysis.

Lab-on-chip are analytical systems which, compared to traditional methods, offer significant reduction of sample, reagent, energy consumption and waste production. Within this framework, we report on the development and testing of an optoelectronic platform suitable for the on-chip detection of fluorescent molecules. The platform combines on a single glass substrate hydrogenated amorphous silicon photosensors and a long pass interferential filter.

This article investigates the stability of hydrogenated amorphous silicon (a-Si:H) p-i-n junctions employed as temperature sensors in lab-on-chip (LoC) applications. The devices have been tested under forward current injection and different temperatures (from room temperature up to 90 °C) in order to reproduce the practical operating conditions. Two sets of devices with different diborane concentrations in the p-doped layer have been investigated as a case study.