657 research outputs found
Wide-Range Optical CMOS-Based Diagnostics
Colorimetric, chemiluminescence and refractive index based diagnostics are some of the most important sensing techniques in biomedical science and clinical medicine. Conventionally laboratories and medical clinics rely on bulky and dedicated equipment for each diagnostic technique independently. In this paper, we present CMOS sensor based solutions, comprising a single photon avalanche detector array and photodiode array. The CMOS platform offers low cost integration and wide range of light-based diagnostic techniques, leading to development of point-of-care devices
A handheld high-sensitivity micro-NMR CMOS platform with B-field stabilization for multi-type biological/chemical assays
We report a micro-nuclear magnetic resonance (NMR) system compatible with multi-type biological/chemical lab-on-a-chip assays. Unified in a handheld scale (dimension: 14 x 6 x 11 cm³, weight: 1.4 kg), the system is capable to detect<100 pM of Enterococcus faecalis derived DNA from a 2.5 μL sample. The key components are a portable magnet (0.46 T, 1.25 kg) for nucleus magnetization, a system PCB for I/O interface, an FPGA for system control, a current driver for trimming the magnetic (B) field, and a silicon chip fabricated in 0.18 μm CMOS. The latter, integrated with a current-mode vertical Hall sensor and a low-noise readout circuit, facilitates closed-loop B-field stabilization (2 mT → 0.15 mT), which otherwise fluctuates with temperature or sample displacement. Together with a dynamic-B-field transceiver with a planar coil for micro-NMR assay and thermal control, the system demonstrates: 1) selective biological target pinpointing; 2) protein state analysis; and 3) solvent-polymer dynamics, suitable for healthcare, food and colloidal applications, respectively. Compared to a commercial NMR-assay product (Bruker mq-20), this platform greatly reduces the sample consumption (120x), hardware volume (175x), and weight (96x)
Balanced ternary addition using a gated silicon nanowire
We demonstrate the proof of principle for a ternary adder using silicon
metal-on-insulator single electron transistors (SET). Gate dependent rectifying
behavior of a single electron transistor results in a robust three-valued
output as a function of the potential of the SET island. Mapping logical,
ternary inputs to the three gates controlling the potential of the SET island
allows us to perform complex, inherently ternary operations, on a single
transistor
Integrated collinear refractive index sensor with Ge PIN photodiodes
Refractive index sensing is a highly sensitive and label-free detection
method for molecular binding events. Commercial implementations of biosensing
concepts based on plasmon resonances typically require significant external
instrumentation such as microscopes and spectrometers. Few concepts exist that
are based on direct integration of plasmonic nanostructures with optoelectronic
devices for on-chip integration. Here, we present a CMOS-compatible refractive
index sensor consisting of a Ge heterostructure PIN diode in combination with a
plasmonic nanohole array structured directly into the diode Al contact
metallization. In our devices, the photocurrent can be used to detect surface
refractive index changes under simple top illumination and without the aid of
signal amplification circuitry. Our devices exhibit large sensitivities > 1000
nm per refractive index unit in bulk refractive index sensing and could serve
as prototypes to leverage the cost-effectiveness of the CMOS platform for
ultra-compact, low-cost biosensors.Comment: 21 pages, 6 figures, supporting information with 11 pages and 11
figures attache
Highly uniform and low-loss passive silicon photonics devices using a 300mm CMOS platform
Using an advanced 300mm CMOS-platform, we report record-low and highly-uniform propagation loss: 0.45 +/- 0.12dB/cm for wires, and 2dB/cm for slot waveguides. For WDM devices, we demonstrate channel variation(3-sigma) within-wafer and within-device of 6.1nm and 1.2nm respectively
High-Q photonic crystal nanocavities on 300 mm SOI substrate fabricated with 193 nm immersion lithography
On-chip 1-D photonic crystal nanocavities were designed and fabricated in a 300 mm silicon-on-insulator wafer using a CMOS-compatible process with 193 nm immersion lithography and silicon oxide planarization. High quality factors up to 10(5) were achieved. By changing geometrical parameters of the cavities, we also demonstrated a wide range of wavelength tunability for the cavity mode, a low insertion loss and excellent agreement with simulation results. These on-chip nanocavities with high quality factors and low modal volume, fabricated through a high-resolution and high-volume CMOS compatible platform open up new opportunities for the photonic integration community
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