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Pasqualina M. Sarro - IEEE Xplore Author Profile

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A repeatable method to fabricate multi-layer graphene (ML-gr) membranes of 2r = 85 – 155 μm (t < 10 nm) with a 100% yield on 100 mm wafers is demonstrated. These membranes show higher sensitivity than a commercial MEMS-Mic combined with an area reduction of 10x. The process overcomes one of the main limitations when integrating graphene diaphragms in microphones due to the absence of automatic tra...Show More
We present a novel design of elastic micropillars for tissue self-assembly in engineered heart tissue (EHT) platforms. The innovative tapered profile confines reproducibly the tissue position along the main micropillar axis, increasing the accuracy of tissue contraction force measurement. Polydimethylsiloxane-based pillars were designed and fabricated by wafer-level molding in an hourglass shape, ...Show More
Sensing flow rates in structured microenvironments like lab-on-chip (LOC) and organ-on-chip (OoC) is crucial to assess important parameters such as transport of media and molecules of interest. So far, these micro-electromechanical systems for biology (bio-MEMS) mostly rely on flow sensing systems based on thermal sensors. However, thermal flow sensing has limitations, since the measurement princi...Show More
An angle sensitive optical sensor without conventional optics is presented in this article. The reported device omits the need for adding 3-D optics in postprocessing by monolithic integration of complimentary metal-oxide semiconductor compatible diffraction grating layers, which cuts down the fabrication costs and allows for miniaturization of these types of sensors. The sensor resolves angular i...Show More
In this paper, we present a quadrant sun position sensor microsystem device in a silicon carbide technology that operates in a field-of-view of ±33° and reaches a mean error of 1.9° in this range. This will allow, for the first time, an inherently visible blind sun position sensor in a CMOS compatible technology. Opto-electronic integration of the photodetectors and CMOS readout circuitry on-chip ...Show More
We present preliminary recordings on chip of three-dimensional (3D) electric neuronal activity from cultures of cortical neurons derived from human-induced pluripotent stem cells (hiPSCs). The recordings were obtained through 3D microelectrode arrays (MEAs) composed of truncated, 90 μm-high Si micropyramids endowed with multiple, electrically distinct, and vertically arranged TiN microelectrodes. ...Show More
The wide bandgap of silicon carbide (SiC) has attracted a large interest over the past years in many research fields, such as power electronics, high operation temperature circuits, harsh environmental sensing, and more. To facilitate research on complex integrated SiC circuits, ensure reproducibility, and cut down cost, the availability of a low-voltage SiC technology for integrated circuits is o...Show More
Accurately sensing the temperature in silicon carbide (power) devices is of great importance to their reliable operation. Here, temperature sensors by resistive and CMOS structures are fabricated and characterized in an open silicon carbide CMOS technology. Over a range of 25-200°C, doped design layers have negative temperature coefficients of resistance, with a maximum change of 79%. Secondly, CM...Show More
Stemming from the convergence of tissue engineering and microfluidics, organ-on-chip (OoC) technology can reproduce in vivo-like dynamic microphysiological environments for tissues in vitro. The possibility afforded by OoC devices of realistic recapitulation of tissue and organ (patho)physiology may hold the key to bridge the current translational gap in drug development, and possibly foster perso...Show More
Continuous monitoring of tissue microphysiology is a key enabling feature of the organ-on-chip (OoC) approach for drug screening and disease modeling. Sensing charged species in OoC tissue microenvironments is thereby essential. However, the inherently small (i.e., cm) size of OoC devices poses the challenging requirement to integrate miniaturized and highly sensitive in situ charge sensing compon...Show More
In this paper, we report a modified three step anisotropic wet etching (TSWE) method to fabricate solid-state silicon nanoslits. The slit-opening process is performed by crystal plane etching. The etching rate of the crystal plane is reasonably slow as it is only 1/45 of the etching rate, thus allowing and therefore good slits-opening controllability. By slowly etching the ...Show More
Based on our proposed precision two-step gate recess technique, a suspended gate-recessed Pt/AlGaN/GaN heterostructure gas sensor integrated with a micro-heater is fabricated and characterized. The controllable two-step gate recess etching method, which includes O2 plasma oxidation of nitride and wet etching, improves gas sensing performance. The sensitivity and current change of the AlGaN/GaN het...Show More
In this paper we present a sun position sensor platform with a scalable approach for the 3D integration of the sensor optics. This would facilitate the sun position sensor miniaturization, reduces fabrication cost and mitigates the need for sensor calibration. The sun position sensor platform is implemented in a seven mask BICMOS technology with optical windows between the light masking layer and ...Show More
This paper describes the microfabrication and electrical characterization of aluminum-coated superconducting through-silicon vias (TSVs) with sharp superconducting transition above 1 K. The sharp superconducting transition was achieved by means of fully conformal and void-free DC-sputtering of the TSVs with Al, and is here demonstrated in up to 500 μm-deep vias. Full conformality of Al sputtering ...Show More
We present a wafer-scale fabricated, PDMS-based platform for culturing miniaturized engineered heart tissues (EHTs) which allows highly accurate measurements of the contractile properties of these tissues. The design of the platform is an anisometrically downscaled version of the Heart-Dyno system, consisting of two elastic micropillars inside an elliptic microwell with volume ranging from 3 down ...Show More
Organ-on-chip (OoC) devices are in rising demand for high-throughput and low-cost development and toxico-logical screening of chemicals and pharmaceuticals, as they accurately mimic in vitro physiological conditions as in the human body. In particular, OoCs are urgently needed for screening cardiovascular drug toxicity. Physiological relevance of cardiovascular cell cultures requires moving substr...Show More
This paper presents the fabrication and electrical characterization of superconducting high-aspect ratio through-silicon vias DC-sputtered with aluminum. Fully conformal and void-free coating of 300 μm-deep and 50 μm-wide vias with Al, a CMOS-compatible and widely available superconductor, was made possible by tailoring a funneled sidewall profile for the axisymmetric vias. Single-via electric res...Show More
The present work reports on the hydrogen gas detection properties of Pt-AlGaN/GaN high electron mobility transistor (HEMT) sensors with recessed gate structure. Devices with gate recess depths from 5 to 15 nm were fabricated using a precision cyclic etching method, examined with AFM, STEM and EDS, and tested towards H2 response at high temperature. With increasing recess depth, the threshold volta...Show More
We describe a microfabrication process that, thanks to a specifically tailored sidewall profile, enables for the first-time wafer-scale arrays of high-aspect ratio through-silicon vias (TSVs) coated with DC-sputtered Aluminum, achieving at once superconducting and CMOS-compatible 3D interconnects. Void-free conformal coating of up to 500 μm-deep and 50 μm-wide vias with a mere 2 μm-thick layer of ...Show More
We present the first Organ-on-Chip equipped with a low-impedance Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) MicroElectrode Array (MEA). The novel device allows simultaneous mechanical stimulation with a stretchable PDMS membrane and electrical monitoring via the PEDOT:PSS MEA of multiple in vitro cell cultures. The surface area enhancement and the morphology of the PEDOT:PS...Show More
Graphene is an attractive material to be used for pressure sensors due to its thinness, electrical conductivity, and potential high gauge factor. One of the issues with processing graphene is the scalability, which is largely limited by the transfer process that is required for graphene deposited by chemical vapour deposition (CVD). In this work we employed a novel, transfer-free bulk-micromachini...Show More
This work reports on the fabrication and characterization of recessed gate Pt-AlGaN/GaN HEMT H2 sensor. The device with partially etched AlGaN layer was obtained by cyclic plasma oxidation and selective chemical oxide etching. The recess depth of 12.3 nm and low RMS roughness were measured by AFM and the Pt/AlGaN interface was examined by STEM. The gate recess resulted in a ~1 V positive threshold...Show More
In this paper we present, for the first time, the successful monolithic wafer-scale integration of CVD graphene with CMOS logic for highly miniaturized smart sensing structures with on-chip readout electronics. The use of a patterned CMOS compatible catalyst for pre-defined regions of CVD graphene growth, and the transfer-free process used, allows the direct implementation of patterned graphene st...Show More
We developed an AlGaN/GaN high electron mobility transistor (HEMT) sensor with a tungsten trioxide (WO3) nano-film modified gate for nitrogen dioxide (NO2) detection. The device has a suspended circular membrane structure and an integrated micro-heater. The thermal characteristic of the Platinum (Pt) micro-heater and the HEMT self-heating are studied and modeled. A significant detection is observe...Show More
A suspended AlGaN/GaN high electron mobility transistor (HEMT) sensor with a tungsten trioxide (WO3) nanofilm modified gate was microfabricated and characterized for ppm-level acetone gas detection. The sensor featured a suspended circular membrane structure and an integrated microheater to select the optimum working temperature. High working temperature (300°C) increased the sensitivity to up to ...Show More