Lab-on-a-chip for biological fluids analysis by spetrophotometry

The healthcare sector is nowadays one of the most dynamic and where the novelty is a strategic and operational imperative. The possibility of increase the quantity and quality of clinical analysis, performed with instantaneous results and outside the clinical laboratories, contributes to a better quality in the health care services and also a better efficiency in the clinical and administrative processes [1]. This possibility can be achieved with the presented lab-on-a-chip for spectrophotometric analysis of biological fluids. It allows the selective measurement of the concentration of several biomolecules in biological fluids, with instantaneous results, at any location, with small quantities of reagents and samples and with low-cost. That measurement is based on colorimetric detection by the optical absorption in a part of the visible spectrum defined by the reaction of the specific biomolecule with a specific reagent. The device comprises a highly efficient and selective optical filtering and colorimetric detection system. This system allows the measurement with a regular white light illumination, thus avoiding the use of complex and expensive analysis systems like the ones that comprise spectrophotometers, for example. This feature highly facilitates portability and ensures analysis within consultation time, at a patient house (allowing a first trial) and in clinical laboratories or hospitals.Fundação para a Ciência e a Tecnologia (FCT) SFRH/BD/1281/2000 Escola de Engenharia da Universidade do Minho - Projecto IN2TEC. Centro Algoritmi da Universidade do Minh

High-selectivity single-chip spectrometer for operation at visible wavelengths

A micro-spectrometer has been realized based on an array of Fabry-Perot thin-film optical resonators. The 16 channel micro-spectrometer is IC fabrication compatible and operates in the visible spectral range with an inter-channel shift of 6 nm. Each of the channels is sensitive in a single peak with FWHM of 16 nm. A FWHM < 2 nm and finesse of 40 for narrowband operation is demonstrated.STW - Project DEL 55.3733. TUDelft. Fundação para a Ciência e Tecnologia - Praxis XXI-BD/5181/95

Micromachined fabry-perot optical filters

The design, fabrication and measured characteristics of micromachined Fabry- Perot (F-P) optical filters for the visible spectral range are presented. Silver films of 40-50 nm thickness, evaporated on a 300 nm thick low-stress silicon nitride membrane, are used as high-quality mirrors. Two parallel mirrors, with a square aperture of up to 2x2 mm2 and initial cavity gap of 1.2 µm, form a tunable Fabry- Perot optical filter. One of the mirrors is fixed the other is under tension on a movable Si frame, which is electrostatically deflected to control the mirror spacing and parallelism. Results are compared with non-tunable F-P filters that are composed of an Ag/SiN/Ag or Ag/SiO2/Al layer stack. The FWHM of 40 nm (tunable filter) and 16 nm (non-tunable filter) have been achieved.STW - Project DEL 55.3733. Junta Nacional de Investigação Científica e Tecnológica - PRAXIS XXI-BD/5181/95

High-selectivity single-chip spectrometer in silicon for operation at visible part of the spectrum

A microspectrometer has been realized based on an array of Fabry–Perot optical thin-film filters. The 16-channel microspectrometer is compatible with IC fabrication methods and operates in the visible spectral range with an interchannel shift of 6 nm. Each of the channels is sensitive in a single peak with full-width-half-maximum (FWHM) of 16 nm. Also aFWHMbelow 2 nm and finesse of 40 for narrow band operation is demonstrated. The device can easily be tuned during fabrication to cover a different spectral band only by adjusting the etching times without affecting the device layout. Such a device is extremely suitable for applications in microsystems because of its small size, high spectral selectivity, and low cost. Microspectrometers for the UV and IR regions are also feasible using this technique.Fundação para a Ciência e a Tecnologia (FCT

Silver-based reflective coatings for micromachined optical filters

Silver films of 40 nm thickness, evaporated on a 300 nm thick low-stress silicon nitride layer, are used as high-quality mirrors operating in the visible and near IR spectral range. Application of a silicon nitride membrane under tension, placed within a square Si frame after bulk micromachining, improves the initial mirror flatness. Two parallel mirrors, each with square aperture of up to 2x2 mm2 and an electrostatically controlled spacing, form a tunable Fabry–P´erot optical filter. Investigation of the silver-based reflective coatings, and mirror characterization, including influence of bulk micromachining, are presentedFundação para a Ciência e a Tecnologia FC

Bulk-micromachined tunable fabry–perot microinterferometer for the visible spectral range

The design, fabrication and measured characteristics of a bulk-micromachined tunable Fabry–Perot microinterferometer (FPMI) for the visible spectral range are presented. The FPMI is formed by two parallel 40 nm thick silver mirrors supported by a 300 nm low tensile stress silicon nitride membrane with a square aperture (side length of 2 mm) and initial cavity gap of 1.2 µm. One of the mirrors is fixed, the other is under tension on a movable Si frame, which is electrostatically deflected, using several distributed electrodes, to control cavity spacing and mirror parallelism. Performance achieved is: high flatness of the mirrors (λ/10 for the visible part of the spectrum), low control voltages (<21 V for 450 nm deflection) and simple fabrication.Fundação para a Ciência e Tecnologia (FCT

A local bus for MCM-based microinstrumentation systems

A local bus is described which is designed for use in a multi-chipcomposed microinstrumentation system. The bus is able to transmit a digital code, bitstream, analog voltage, frequency, duty-cycle and also provides calibration facilities, service request and interrupt request for the smart sensors. Corresponding sensor bus interface was implemented in a 1.6 m CMOS process and successfully tested in a local sensor network.Junta Nacional de Investigação Científica e Tecnológica - Praxis XXI-BD/5181/95. STW - Project DEL 55.3733. TUDelft

A microinstrumenation system for industrial applications

This paper describes the development of a microinstrumentation system in silicon containing all the components of the data acquisition system, such as sensors, signal-conditioning circuits, analog-digital converter, interface circuits, sensor bus interface, and an embedded microcontroller (MCU). The microinstrumentation system is to be fabricated using the Multi-Chip-Module (MCM) technology based on a chip-level infrastructure. A standard silicon platform is the floorplan for individual smart sensor die attachment and an on-chip local sensor bus interface, testing facilities, optional compatible sensors (such as thermal sensors). The microinstrumentation system is controlled by a MCU with several modes of low-power operation (inclusive stand-by mode). As the intended application requires a huge amount of data-processing, a RISC-type MCU architecture is to be used. The MCU communicates with the front-end sensors via a two-line (clock and data lines) intramodule sensor bus (Integrated Smart Sensor bus). The sensor scan rate is adaptive and can be event triggered. This upgraded version of the ISS bus allows: service and interrupt request from the sensors, test and calibration facilities. However, the additional functionality requires a third line. The MCU also controls the power consumption and the thermal budget of all system. This paper also presents three applications for the microinstrumentation system: condition monitoring of machines, an inertial navigation system and a miniature spectrometer.STW - Project DEL55.3733. TUDelft. Junta Nacional de Investigação Científica e Tecnológica - Praxis XXI-BD/5181/95

A local bus for multi-chip-module-based microinstrumentation systems

A local smart bus is described which is designed for use in muti-chip-composed microinstrumentation system. The bus is able to transmit a digital code, bitstream, analog voltage, frquency, duty-cycle and also provides calibration facilities, service request and interrupt request modes.FC

A low-power low-voltage digital bus interface for MCM-based microsystems

Comunicação apresentada na 23rd European Solid-State Circuits Conference (ESSCIRC '97), Southampton, UK, 16-18 September 1997.This paper describes a digital local bus interface, which is designed for use in a multi-chip-composed microsystem. The chip area using a CMOS 1.6mm n-well technology is 1mm2. Power consumption at 5V@100kHz is less than 500mW and for 5V@4MHz less than 2mW due to a smart power management of all functional blocks. The bus interface is able to transmit a digital code, bitstream, analog voltage, frequency, duty-cycle and also provides calibration facilities, service request and interrupt request for the smart sensors or microactuators.Junta Nacional de Investigação Científica e Tecnológica - Praxis XXI-BD/5181/95. STW - Project DEL 55.3733. TUDelft