A technique is described for the measurement of fluid temperatures in microfluidic systems based on temperature-dependent fluorescence. The easy to implement with a standard fluorescence microscope and CCD camera. In addition, method can be used measure micrometer spatial resolution millisecond time resolution. efficacy demonstrated by measuring temperature distributions resulting from Joule heating variety circuits that are electrokinetically pumped. With equipment these measurements,...

Microfluidic devices have been fabricated on poly(methyl methacrylate) substrates by two independent imprinting techniques. First-generation were using a small-diameter wire to create an impression in plastics softened low-temperature heating. The resulting are limited only simple linear channel designs but readily produced at low cost. Second-generation with more complex microchannel arrangements the plastic inverse three-dimensional image of device micromachined silicon wafer. This...

Traditional liposome preparation methods are based on mixing of bulk phases, leading to inhomogeneous chemical and/or mechanical conditions during formation; hence liposomes often polydisperse in size and lamellarity. Here we show the formation that encapsulate reagents a continuous two-phase flow microfluidic network with precision control from 100 300 nm by manipulation liquid rates. We demonstrate creating solvent−aqueous interfacial region format is homogeneous controllable length scale...

Large spiral inductors encased in oxide over silicon are shown to operate beyond the UHF band when capacitance and loss resistance greatly reduced by selective removal of underlying substrate. Using a 100-nH inductor whose self-resonance lies at 3 GHz, balanced tuned amplifier with gain 14 dB centered 770 MHz has been implemented standard digital 2- mu m CMOS IC process. The core noise figure is 6 dB, power dissipation 7 mW for 3-V supply.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML"...

We investigate the formation of unilamellar lipid vesicles (liposomes) with diameters tens nanometers by controlled microfluidic mixing and nanoparticle determination (COMMAND). Our study includes liposome synthesis experiments numerical modeling our implementation batch solvent injection method. consider from perspective fluid interfaces convective-diffusive mixing, as we find that bulk flow parameters including hydrodynamically focused alcohol stream width, final concentration, shear...

A new method to tailor liposome size and distribution in a microfluidic format is presented. Liposomes are spherical structures formed from lipid bilayers that tens of nanometers several micrometers diameter. Liposome tailored for particular application inherently important vivo applications such as drug delivery transfection across nuclear membranes gene therapy. Traditional laboratory methods preparation require postprocessing steps, sonication or membrane extrusion, yield formulations...

A monolithic tin oxide (SnO/sub 2/) gas sensor realized by commercial CMOS foundry fabrication (MOSIS) and postfabrication processing techniques is reported. The device composed of a sensing film that sputter-deposited on silicon micromachined hotplate. technique requires no masking utilizes in situ process control monitoring resistivity during growth. Microhotplate temperature controlled from ambient to 500 degrees C with thermal efficiency 8 C/mW response time 0.6 ms. Gas responses pure...

A simple model to describe radiation effects on MOSFET electrical characteristics is presented. The key assumption that mobility degradation in an enhancement mode predominantly due charged interface traps. Model predictions are compared with measured values of trap density and device I - V curves.

Electroosmotic flow (EOF) is commonly utilized in microfluidics. Because the direction of EOF can be determined by substrate surface charge, control chemical state offers potential, addition to voltage control, direct microfluidic devices. We report use polyelectrolyte multilayers (PEMs) alter charge and polystyrene acrylic Relatively complex patterns with simple arrangements applied voltages are realized derivatization different arms a single device oppositely charged polyelectrolytes. In...

A new plastic imprinting method using a silicon template is demonstrated. This approach obviates the necessity of heating substrate during stamping process, thus improving device yield from approximately 10 devices to above 100 per template. The dimensions imprinted microchannels were found be very reproducible, with variations less than 2%. channel depths dependent on pressures applied and materials used. Rather bonding open channels another piece plastic, flexible adhesive...

We present a microfluidic method to direct the self-assembly of temperature-sensitive liposome−hydrogel hybrid nanoparticles. Our approach yields nanoparticles with structural properties and highly monodisperse size distributions precisely controlled across broad range relevant targeted delivery release encapsulated therapeutic agents. used hydrodynamic focusing control convective-diffusive mixing two miscible nanoparticle precursor solutions (a DPPC:cholesterol:DCP phospholipid formulation...

A pulsed UV excimer laser (KrF, 248 nm) was used to modify the surface charge on side wall of hot-embossed microchannels fabricated in a poly(methyl methacrylate) substrate. Subablation level fluences, less than 2,385 mJ/cm2, were prevent any changes physical morphology surface. It is shown that electroosmotic mobility, induced by an electric field applied along length channel, increases average 4% regions have been exposed pulses compared nonexposed regions. Furthermore, application...

This paper presents characteristics of microwave transmission in coplanar waveguides (CPW's) on silicon (Si) substrates fabricated through commercial CMOS foundries. Due to the fabrication, metal strips CPW are encapsulated thin films Si dioxide. Many test sets were with different line dimensions, all p-type resistivities range from 0.4 /spl Omega//spl middot/cm 12.5 middot/cm. Propagation constant and characteristic impedance measurements performed at frequencies 0.1 40 GHz, using a...

We describe an operating mode of a gas sensor that greatly enhances the capability device to determine composition sensed gas. The consists micromachined hotplate with integrated heater, heat distribution plate, electrical contact pads, and sensing film. temperature programmed (TPS) technique uses millisecond timescale changes modify rates for adsorption, desorption, reaction gases on surface during operation. A repetitive train pulses produces patterned conductance response depends...

Fabrication of thermally isolated micromechanical structures capable generating thermal radiation for dynamic scene simulation (DTSS) is described. Complete compatibility with a commercial CMOS process achieved through design novel, but acceptable, layout implementation by the foundry using its regular sequence. Following production and delivery chips, single maskless etch in an aqueous ethylemediamine-pyrocatechol mixture performed to realize structures. The resulting are suspended plates...

The ability to selectively and precisely control the temperature of fluid volumes ranging from a few microliters sub-nanoliters in microfluidic networks is vital for wide range applications micro total analysis systems (μTAS). In this work, we characterize model performance thin film microwave transmission line integrated with channel heat fluids relevant buffer salt concentrations over frequencies. A microchannel fabricated poly(dimethylsiloxane) (PDMS) aligned coplanar waveguide (CPW)...

Coplanar waveguides were designed and fabricated through a commercial CMOS process with post-processing micromachining. The transmission-line layouts computer-aided design (CAD) tools. Integrated circuits (ICs) the MOSIS service, subsequently suspended by top-side etching. absence of lossy silicon substrate after etching results in significantly improved insertion-loss characteristics, dispersion phase velocity. Two types layout are presented for different ranges characteristic impedance....

This work describes an implementation of a thermoelectric microwave power sensor fabricated through commercial CMOS process with additional maskless etching. The combines micromachined coplanar waveguide and contact pads, termination which dissipates heat proportionally to input power, many aluminum-polysilicon thermocouples. device was designed in standard technology, including the appropriate superimposed dielectric openings for post-fabrication micromachining. By removing bulk silicon...

A major limitation in the fabrication of microstructures as a postCMOS (complimentary metal oxide semiconductor) process has been overcome by development hybrid processing technique, which combines both an isotropic and anisotropic etch step. Using this microelectromechanical structures with sizes ranging from 0.05 to /spl sim/1 mm width up 6 length were fabricated CMOS technology. The mechanical robustness determines limit on their dimensions. Examples application technique produce...

Rapid, robust, and economical fabrication of fluidic microchannels is fundamental importance for the successful development disposable lab-on-a-chip devices. In this work, we present a solvent-actuated bonding method fabricating polymeric microfluidic devices at room temperature. A PMMA sheet with an imprinted microchannel was clamped to blank sheet, then 80 +/- 5 muL acetone (bonding solvent) introduced one end channel aspirated out other end. As solvent moved down channel, capillary forces...