Hybrid Chip Research Articles

A hybrid microdevice with a thin PDMS membrane on the detection window for UV absorbance detection

We exploited a PDMS-quartz hybrid microchip with a thin PDMS membrane on the concave detection window for UV absorbance detection. The thickness of the PDMS membrane is about 100 mum, with high UV transmittance. As compared to a PDMS-quartz hybrid chip with a common detection window, the proposed one exhibited over an one order of magnitude sensitivity enhancement, and an about two orders of magnitude S/N increase for gastrodin (p-hydroxymethylphenyl-beta-D-glucopyranoside). In addition, the limit of the detection wavelength has been extended from 240 to 210 nm, which is otherwise impossible for a traditional PDMS-quartz hybrid microchip. This kind of microchip has the potential for a large range of applications in an integrated microfluidic system with UV detection.

Signal-Amplifying Conjugated Polymer–DNA Hybrid Chips

So geht's besser: Signalverstärkende DNA-Chips wurden durch lichtgesteuerte On-Chip-DNA-Synthese auf einem dünnen Film aus einem photostabilen konjugierten Polyoxadiazol-Derivat hergestellt. Das Fluoreszenzsignal einer mit Hexachlorfluorescein markierten Ziel-DNA war nach der DNA-DNA-Hybridisierung wegen eines effizienten Förster-Energietransfers vom konjugierten Polymer zum Farbstoff deutlich intensiver als das Signal eines Kontrollfilms.

Signal‐Amplifying Conjugated Polymer–DNA Hybrid Chips

Bio-/synthetic hybrid materials have recently received considerable attention owing to their potential biomedical applications. The most reliable way of identifying any biological target is through its genetic code. However, the current commercial DNA microarray requires costly and time-consuming PCR to multiply the number of analyte DNA molecules and label the analyte DNA with a fluorescent dye because of the low detection limit. In this context, devising self-signal-amplifying DNA microarrays can realize low-cost, fast, and reliable detection of nucleic acids. Herein, we report signal-amplifying DNA chips fabricated by on-chip DNA synthesis on a thin film of a newly developed conjugated polymer (Figure 1 and the chemical structure in Figure 2a).

Chalcogenides amass off-stage

Compound materials have made the headlines in recent semiconductor developments, which includes the Ohio-based researchers' new magnetic-semiconductor bi-layer of GaN and MnGa for spin control (which will operate at room temperatures), and to Intel and UCSB's development of a hybrid chip of light-emitting InP combined with silicon. But at this December's IEDM, one spotlight is on chalcogenide memories or phase change materials. Judging by patent activity, and some of the developments in 2006, this could become another ‘must have’ characteristic for advanced memories, though dates for wide availability range from 2008 to 2010.

A capillary–PDMS hybrid chip for separations-based sensing of neurotransmitters in vivo

A chip fabricated by multilayer soft lithography of poly(dimethylsiloxane) was created for separations-based sensing of neurotransmitters in vivo. The chip incorporated a pneumatically actuated peristaltic pump and valving system to combine low-flow push-pull perfusion sampling, on-line derivatization, and flow-gated injection onto an embedded fused-silica capillary for high speed separation of amine neurotransmitters from the brain of living animals. Six 160 microm wide by 10 microm high control channels, actuated with an overlapping 60 degrees pulse sequence, simultaneously drove sample and buffers through fluidic channels of the same dimensions. Tunable sampling flow rates of 40 to 130 nL min(-1) and separation buffer flow rates of 380 to 850 nL min(-1) were achieved with actuation frequencies between 3 and 10 Hz. On-line sampling of amine neurotransmitters with separation efficiencies in excess of 250,000 plates, detection limits of approximately 40 nM, and relative standard deviations of 4% for glutamate and aspartate were achieved in vitro. Electropherograms with resolution of gamma-aminobutyric acid, glutamine, taurine, serine, glycine, o-phosphorylethanolamine, glutamate, and aspartate could be collected every 30 s for over 4 h in vivo. It was also shown that pharmacological agents could be delivered and subsequent changes in neurotransmitter profile could be measured when delivering either 70 mM K+ artificial cerebrospinal fluid or 200 microM l-trans-pyrrolidine-2,4-dicarboxilic acid with the chip. These results demonstrate the ability of this chip to sample and monitor chemicals in the complex environment of the central nervous system with high selectivity and sensitivity over extended periods.

Microfluidic Devices for Molecular Monitoring of Clonotypic IgH VDJ Signatures and the T(4;14) Translocation in Multiple Myeloma.

Integrated microfluidic chips offer fast, inexpensive and sensitive detection of molecular characteristics of cancer. PCR was performed using a hybrid polymer/glass chip comprising of wells and channels moulded in polydimethyl siloxane (PDMS) using photolithographic procedures and bonded to glass by a simple rapid prototyping procedure. Fluidic flow was performed by a microprocessor with an in-house built intelligent system for a fully reusable, scalable valving and pumping operation. We successfully performed on-chip PCR with 2 ul of template/PCR mix. Multiple Myeloma (MM) is characterized by a distinct immunoglobulin gene rearrangements, and by IgH translocations that enable unequivocal identification of the MM clone. To detect these molecular signatures, PCR was performed in the central enclosed chamber of a 3-well PCR chip (the other two being the loading and the unloading open wells) using fluorescent-tagged primers, operated using miniaturized user controlled instrumentation. After PCR amplification, product was detected by fragment analysis on a glass capillary electrophoresis (CE) chip using 50–250pl of the amplified product, performed in about 2 minutes. Unlike PCR using plasmid templates, successful PCR using nucleic acid from patient cells required passivation of the PDMS and glass inner surfaces to minimize adsorption of PCR components, and the use of approximately 1–2ng of cDNA template. Amplified products were run through a polymer filled separation channel with size standards to confirm the product size. For two MM patients, using the CE chip, both genomic DNA and IgH VDJ transcripts amplified from individual cells are detectable on-chip with as little as 0.001% of the product (50pL) amplified from one individual MM cell or from groups of MM cells. IgH VDJ product was detectable on the CE chip after a single stage conventional PCR of 30 cycles to amplify genomic DNA from 100 ex-vivo MM cells (100 copies of template). For detection of the single rearranged copy of IgH VDJ in genomic DNA from individual MM cells, a nested PCR strategy was required to amplify sufficient product for detection using either on chip CE or the ABI3100. Compared to analysis on the ABI3100, the gold standard technology, the chip provided approximately 20 fold greater sensitivity for detecting fluorescent product. To further test the microfluidic system, we amplified cDNA from ex-vivo MM cells having the t(4;14)+ translocation to detect hybrid transcripts (IgH-MMSET) on-chip. Cells from MM patients having either the MB4-1 or MB4-3 breakpoint were amplified using the PDMS/glass hybrid chip, and products of the appropriate size were detected using either conventional or on-chip CE. Finally, PCR was performed on an integrated chip that seamlessly incorporates both the PCR and the CE components as a single unit with minimal manual intervention, aiming towards higher levels of on-chip integration. Work is in progress to implement sample processing and cell selection on-chip. This work forecasts automated cost-effective devices able to analyze genetic information in minutes. Real-time detection of complex genetic abnormalities will allow sensitive detection of emerging aggressive variants as disease progresses. This will enable custom tailored therapies that target the genetic vulnerabilities of the malignant clone in each individual patient.

Dynamic coating for resolving rhodamine B adsorption to poly(dimethylsiloxane)/glass hybrid chip with laser-induced fluorescence detection

In this paper a method was described about dynamic coating for resolving rhodamine B (RB) adsorption on a hybrid poly(dimethylsiloxane) (PDMS)/glass chip. The results showed that when the non-ionic surfactant Triton X-100 was higher than 0.5% (v/v) into the phosphate buffer, the adsorption of RB appeared. Besides, some separation conditions for RB were investigated, including concentration of Triton X-100, concentration and pH value of running buffer, separation voltage and detection site. Through comparing electroosmotic flow, plate numbers and other parameters, an acceptable separation condition was obtained. Under optimized conditions, the precisions of RB detection (R.S.D., n = 10) were 2.62% for migration time, 4.78% for peak height respectively. Additionally, RB concentration linearity response was excellent with 0.9996 of correlation coefficient between 1 and 100 μM, and a limit of detection (S/N = 3) was 0.2 μM. Finally, we separated rhodamine B isothiocyanate and lysine deriving from the fluorescent probe, and the result displayed that the dynamic coating method was applicable by CE separations using PDMS/glass chip.

Disposable polydimethylsiloxane/silicon hybrid chips for protein detection

This paper presents disposable protein analysis chips with single- or four-chamber-constructed from poly(dimethylsiloxane) (PDMS) and silicon. The chips are composed of a multilayer stack of PDMS layers that sandwich a silicon microchip. This inner silicon chip features an etched array of micro-cavities hosting polymeric beads. The sample is introduced into the fluid network through the top PDMS layer, where it is directed to the bead chamber. After reaction of the analyte with the probe beads, the signal generated on the beads is captured with a CCD camera, digitally processed, and analyzed. An established bead-based fluorescent assay for C-reactive protein (CRP) was used here to characterize these hybrid chips. The detection limit of the single-chamber protein chip was found to be 1 ng/ml. Additionally, using a back pressure compensation method, the signals from each chamber of the four-chamber chip were found to fall within 10% of each other.

Microfluidic channel fabrication in dry film resist for production and prototyping of hybrid chips

Microfluidic networks are patterned in a dry film resist (Ordyl SY300/550) that is sandwiched in between two substrates. The technique enables fabrication of complex biochips with active elements both in the bottom and the top substrate (hybrid chips). The resist can be double bonded at relatively low temperatures without the use of extra adhesives. A postbake transfers the resist into a rigid structure. The resist is qualified in terms of resolution, biocompatibility and fluidic sealing. Fabrication in both a fully equipped cleanroom setting as well as a minimally equipped laboratory is described. The technique is applied for dielectrophoresis-based cell separation systems and a fuel cell reaction chamber with micropillars. The dry film resist can be considered a cheap and fast alternative to SU-8.

Direct electrochemical detection of glucose in human plasma on capillary electrophoresis microchips

We developed an electrochemical detector on a hybrid chip for the determination of glucose in human plasma. The microchip system described in this paper consists of a poly(dimethylsiloxane) (PDMS) layer containing separation and injection channels and an electrode plate. The copper microelectrode is fabricated by selective electroless deposition. The fabrication of the decoupler is performed by platinum electrochemical deposition on the metal film formed by electroless deposition. Factors influencing the performance, including detection potential, separation field strength, and buffer concentration, were studied. The electrodes exhibited good stability and durability in the analytical procedures. Under optimized detection conditions, glucose responded linearly from 10 microM to 1 mM. Finally, glucose in human plasma from three healthy individuals and two diabetics was successfully determined, giving a good prospect for a new clinical diagnostic instrument.

Programming models for hybrid FPGA-cpu computational components: a missing link

Emerging hybrid chips containing cpu and FPGA components are an exciting new development promising commercial off-the-shelf economies of scale, while also supporting hardware customization.

Multichip module with planar-integrated free-space optical vector-matrix-type interconnects.

Even in the semiconductor industry, free-space optical technology is nowadays seen as a prime option for solving the continually aggravating problem with VLSI chips, namely, that the interconnect technology has failed to keep pace with the increase in communication volume. To make free-space optics compatible with established lithography-based design and fabrication techniques the concept of planar integration was proposed approximately a decade ago. Here its evolution into a photonic microsystems engineering concept is described. For demonstration, a multichip module with planar-integrated freespace optical vector-matrix-type interconnects was designed and built. It contains flip-chip-bonded vertical-cavity surface emitting laser arrays and a hybrid chip with an array of multiple-quantum-well p-i-n diodes on top of a standard complementary metal-oxide semiconductor circuit as key optoelectronic hardware components. The optical system is integrated into a handy fused-silica substrate and fabricated with surface-relief diffractive phase elements. It has been optimized for the given geometrical and technological constraints and provides a good interconnection performance, as was verified in computer simulations on the basis of ray tracing and in practical experiments.

Multi-user, 10Gb/s spectrally phase coded O-CDMA system with hybrid chip and slot-level timing coordination

We demonstrate a multi-user, 10Gb/s spectrally phase coded O-CDMA system with hybrid chip and slot-level timing coordination utilizing low power nonlinear processing. A new double Hadamard coding scheme is demonstrated to enable both chip-level timing coordination and full interference suppression without the need for synchronous detection.

Programming models for hybrid CPU/FPGA chips

Designers of embedded and real-time systems are continually challenged to meet tighter system requirements at better price-performance ratios. Best-practice methods have long promoted the use of commercial-off-the-shelf components to reduce design costs and time to market, but creating COTS components that are reusable in a wide range of applications remains difficult. In part, the challenge lies in satisfying the contradictory design forces of generalization and specialization. Systems designers are all too familiar with the tension these opposing forces cause in trying to balance cost versus performance. Adopting COTS components reduces costs and time to market but often fails to meet the most demanding performance requirements; custom-designed components can achieve significantly higher performance but at greater development costs and longer times to market. Emerging hybrid chips containing both CPU and field-programmable gate array (FPGA) components are an exciting new development. They promise COTS economies of scale while also supporting significant hardware customization. Components that combine a CPU and reconfigurable logic gates need a programming model that abstracts the computational hardware.

The Effects of Precision Constraints in a Backpropagation Learning Network

This paper presents a study of precision constraints imposed by a hybrid chip architecture with analog neurons and digital backpropagation calculations. Conversions between the analog and digital domains and weight storage restrictions impose precision limits on both analog and digital calculations. It is shown through simulations that a learning system of this nature can be implemented in spite of limited resolution in the analog circuits and using fixed point arithmetic to implement the backpropagation algorithm.

Termal packaging limit for hybrid superconductor-semiconductor electronic circuits.

The discovery of superconductivity above 90K opens up the possibility of powerful hybrid electronic circuits. Superconductive electronic devices exhibit effects of temperature not present in semiconductors. Heat dissipations in transistors cause temperature fields in hybrid chips that affect the performance of the superconductive element, the Josephson junctions. The minimum distance between semiconductor and superconductor elements results in a thermal packaging limit for hybrid chips. This work presents a novel methodology to determine this limit, based on the basic thermal phenomena in superconductive elements. An approximate one-dimensional thermal analysis of a generic hybrid chip design determines the temperature field and the minimum distance.

Interfacing slave designs to FASTBUS: practical experience

The authors have designed a number of FASTBUS slave modules, using a standard interface circuit and standard design-verification tools based on computer-aided-engineering (CAE) techniques. They describe the standard interface and the design and verification methodology. The interface logic for FASTBUS slaves is divided into three blocks: the slave control logic, slave address/data logic, and slave support logic. The control logic is a hybrid chip that handles the protocol portion of the interface. The slave address/data logic includes the functions performed by the address/data interface chip and additional data-path related components, i.e. registers, buffers, and level shifters. The support logic is additional logic necessary to glue the other blocks and application logic together. >

Advances in hybrid chip placement : J. A. M. Van Buul and R. S. Gnant. Semiconductor int., 102 (September 1987)

Advances in hybrid chip placement : J. A. M. Van Buul and R. S. Gnant. Semiconductor int., 102 (September 1987)

Gallium-Arsenide FET Logic Pseudorandom Code Generator

Several configurations of GaAs D flip-flops have been produced and have operated at toggle rates as high as 2790 Mbit/s with dc power consumptions of 150 mW/flip-flop. One flip-flop configuration, operating to 2170 Mbit/s has been employed in a microwave hybrid chip and wire four-stage pseudorandom code generator. This circuit operated to 1035 Mbit/s. High yields of reproducible parts have been obtained. The devices have withstood normal handling and processing steps associated with practical circuit usage.

The Use of Acoustic Emission in a Test for Beam-Lead, TAB, and Hybrid Chip Capacitor Bond Integrity

The use of acoustic emission (AE) in a test for beam-lead bond and anchor integrity has been investigated. AE refers to the emission of broad-band stress waves when materials are broken, cracked, or deformed. A major problem in the present work was to develop means of nondestructively stressing the delicate, irregularly extending beam leads. The most promising of the methods developed are a silicone rubber (SR) pull test, a push down test on SR-encapsulated devices, and various probe methods of applying force to the beams without contacting the chip. AE bursts from weak bonds or beam anchors axe detected with a substrate detector operating at 375 kHz or a probe detector operating at 1.1 MHz or both. The study has revealed considerable difference in the mechanical integrity of beam-lead bond-anchor systems. General deterioration of the beam-anchor system begins at pull forces per beam of approximately 1.0-2.5 gramsforce (gf), depending on the manufacturer's procedure. The forces applied to the beam-anchor system for all methods of stressing, except the pull test, are dependent upon the shape of the individual beams as they extend from the chip, as well as the uniformity of the bugging height. There are many other potential uses of AE in electronics, such as to insure the bonding integrity of flip chips, capacitor chips in hybrids, and bonds on tape automated bonded integrated circuits. The latter two uses were experimentally demonstrated in the present work. Thus it appears that AE will have an increasing role in assuring reliability in the microelectronics field.