Polydimethylsiloxane (PDMS) is a commercially available physically and chemically stable silicone rubber. It has unique flexibility with shear elastic modulus due to one of the lowest glass transition temperatures any polymer . Further properties PDMS are low change in versus temperature , virtually no G frequency high compressibility. Because its clean room processability, curing temperature, flexibility, possibility functional groups very drift time well suited for micromachined mechanical...

In this tutorial review the use of stimulus-sensitive hydrogels as sensors and actuators for (micro)analytical applications is discussed. The first part article aimed at making reader familiar with hydrogels, their chemical composition chemo-physical behavior. prior art in field, that comprises a number ranging from metal ion-sensitive to antigen-sensitive few actuators, also treated part. second focusses on microsensors microactuators well application micro total analysis systems. benefits...

The combination of electrochemistry and spectroscopy, known as spectroelectrochemistry (SEC), is an already established approach. By combining these two techniques, the relevance data obtained greater than what it would be when using them independently. A number review papers have been published on this subject, mostly written for experts in field focused recent advances. In review, both novice more experienced reader, focus not past but future. scope narrowed down to four techniques authors...

Silicon nitride corrugated diaphragms of 2 mm/spl times/2 times/1 /spl mu/m have been fabricated with 8 circular corrugations, having depths 4, 10, or 14 mu/m. The 4-/spl mu/m-deep corrugations show a measured mechanical sensitivity (increase in the deflection over increase applied pressure) which is 25 times larger than flat equal size and thickness. Since this gain due to reduction initial stress, can only case stress. A simple analytical model has proposed that takes influence tensile...

The use of high quality semen for artificial insemination in the livestock industry is essential successful outcome. Insemination using with a number sperm cells containing morphological defects has negative impact on fertilization Therefore, these abnormal discarded order to maintain potential, resulting loss large morphologically normal (up 70-80% original sample). A commonly occurring anomaly cytoplasmic droplet flagella. Currently, no techniques are available extract from rejected...

In this paper a closed-loop controlled micromachined dosing system is presented, for the accurate manipulation of liquids in microsystems down to nanoliter range. The applied driving force dispense originates from electrochemical generation gas bubbles by electrolysis water. proposed comprises channel/reservoir structure silicon, capped with Pyrex® cover on which set platinum electrodes patterned. By adopting an interdigitated electrode geometry, can be used as well simultaneous...

There is a need for capacitance to voltage converters (CVC's) differential capacitive sensors like pressure and accelerometers which can measure both statically dynamically. A suitable CVC described in this paper. The proposed based on symmetrical structure containing two half ac bridges, intrinsically immune parasitic capacitances resistances, capable of detecting changes from dc up at least 10 kHz, able handle single capacitances, easily be realized with discrete components. Its...

Herein, the influence of silicon surface modification via Si-C(n)H(2n+1) (n=10,12,16,22) monolayer-based devices on p-type 100 and n-type is studied by forming MIS (metal-insulator-semiconductor) diodes using a mercury probe. From current density-voltage (J-V) capacitance-voltage (C-V) measurements, relevant parameters describing electrical behavior these are derived, such as diode ideality factor, effective barrier height, flatband voltage, monolayer dielectric constant, tunneling...

A condenser microphone design that can be fabricated using the sacrificial layer technique is proposed and tested. The backplate a 1- mu m plasma-enhanced chemical-vapor-deposited (PECVD) silicon nitride film with high density of acoustic holes (120-525 holes/mm/sup 2/), covered thin Ti/Au electrode. Microphones flat frequency response between 100 Hz 14 kHz sensitivity typically 1-2 mV/Pa have been in reproducible way. These sensitivities achieved relatively low bias voltage 6-16 V. measured...

A pair of interdigitated ultramicroelectrodes (UMEs) is used to electrochemically detect a weak reductor (dopamine) in the presence stronger one (K4[Fe(CN)6]). In mixture both reductors, two electrodes (the generator electrode) oxidize species at 700 mV vs. Ag/AgCl, followed by subsequent (selective) reduction oxidized dopamine 400 mV. regenerated molecule can thus be several times (redox cycling) and enable selective detection even reductor. order obtain high redox cycling efficiency, we...

The costs of drug development have been rising exponentially over the last six decades, making it essential to select candidates in early discovery phases before proceeding expensive clinical trials. Here, we present novel screening methods using an electrochemical chip coupled online mass spectrometry (MS) or liquid chromatography (LC) and MS, generate phase I II metabolites demonstrate protein modification by reactive metabolites. short transit time (∼4.5 s) between oxidation spectrometric...

Mixing fluid samples or reactants is a paramount function in the fields of micro total analysis system (μTAS) and microchemical processing. However, rapid efficient mixing difficult to achieve inside microchannels because difficulty diffusive mass transfer laminar regime typical microfluidic flows. It has been well recorded that efficiency can be boosted by migrating from two-dimensional (2D) three-dimensional (3D) geometries. Although several 3D chaotic mixers have designed, most them offer...

We designed and characterized a microfluidic platform, allowing spatial confinement analysis of individually entrapped sperm cells.