The fabrication, assembly, and initial testing of a hybrid microfabricated gas chromatograph (µGC) is described. µGC incorporates capabilities for on-board calibration, sample preconcentration focused thermal desorption, temperature-programmed separations, "spectral" detection with an integrated array microsensors, designed rapid determinations complex mixtures environmental contaminants at trace concentrations. Ambient air used as the carrier to avoid need supplies. microsystem plumbed...

The current study demonstrates the first surface modification for poly(dimethylsiloxane) (PDMS) microfluidic networks that displays a long shelf life as well extended hemocompatibility. Uncoated PDMS microchannel rapidly adsorb high levels of fibrinogen in blood contacting applications. Fibrinogen adsorption initiates platelet activation, and causes rapid increase pressure across networks, rendering them useless term Here, we describe sealed microchannels using an oxygen plasma pretreatment...

The design, fabrication, and performance of gas chromatography columns etched in silicon substrates are described. Deep reactive-ion etching formed the 3-m-long, 150-μm-wide, 240-μm-deep rectangular cross section channels. A glass cover plate was anodically bonded to remaining surface substrate forming gastight channel. For some columns, channels were oxidized before sealed with plates. Fused-silica capillary connecting tubes into ports on edge 3.2-cm × chips. Dynamic coating used deposit a...

This paper reports the first development of high-performance, silicon-glass micro-gas chromatography (/spl mu/GC) columns having integrated heaters and temperature sensors for programming, pressure flow control. These 3-m long, 150-/spl mu/m wide 250-/spl deep columns, on a 3.3 cm square die, were fabricated using silicon-on-glass dissolved wafer process. Demonstrating contributions to heat dissipation from conduction, convection, radiation with without packaging, it is shown that 7.5-mm...

Blood–material interactions are crucial to the lifetime, safety, and overall success of blood contacting devices. Hydrophilic polymer coatings have been employed improve device lifetime by shielding materials from natural foreign body response, primarily intrinsic pathway coagulation cascade. These ability repel proteins, cells, bacteria, other micro-organisms. Coatings desired long-term stability, so that nonthrombogenic nonfouling effects gained long lasting. Unfortunately, there exist...

Due to the role of nitric oxide (NO) in regulating a variety biological functions humans, numerous studies on different NO releasing/generating materials have been published over past two decades. Although has demonstrated be strong antimicrobial and potent antithrombotic agent, NO-releasing (NOrel) polymers not reached clinical setting. While increasing concentration donor polymer is common method prolong NO-release, this should at cost mechanical strength or biocompatibility original...

Artificial lungs have recently been utilized to rehabilitate patients suffering from lung diseases. However, significant advances in gas exchange, biocompatibility, and portability are required realize their full clinical potential. Here, we focused on the issues of exchange report a small-scale, microfabricated artificial that uses new mathematical modeling bio-inspired design achieve oxygen efficiencies much larger than current devices, thereby enabling air be as ventilating gas. This...

This paper presents the theory, fabrication, and experimental results for a high-performance low-power micro gas chromatography column. The suspended-dielectric 1-m-long column is split into two sections, permitting independent pressure temperature programming. Integrated heaters have mean resistance of 16.8 kOmega coefficient 431 ppm/degC. suspended requires 11 mW to raise its by 100degC in vacuum (1 mtorr). separates ten volatile organic compounds 52 s four chemical warfare agent simulants...

We describe the first microfluidic artificial lung featuring a hemocompatible surface coating and biomimetic blood path its application in an <italic>in vitro</italic> vivo</italic> model.

Although total body perfusion with extracorporeal life support (ECLS) can be maintained for weeks, individual organ beyond 12 hours has yet to achieved clinically. Normothermic ex situ heart (ESHP) offers the potential prolonged cardiac preservation. We developed an ESHP system study effect of perfusate variables on preservation, ultimate goal extending ≥24 hours. Forty porcine hearts were perfused a target Hearts that electromechanical activity and had &lt;3× increase in vascular resistance...

The rapid expansion of microfluidic applications in the last decade has been curtailed by slow, laborious microfabrication techniques. Recently, microfluidics explored with additive manufacturing (AM), as it gained legitimacy for producing end-use products and 3D printers have improved resolution capabilities. While AM satisfies many shortcomings current techniques, there still lacks a suitable replacement most used material devices, poly(dimethylsiloxane) (PDMS). Formulation gas-permeable,...

This study is focused on the application of a dual surface coating poly(dimethylsiloxane) (PDMS) flow chambers, which aims to inhibit contact activation pathway coagulation. Polyethylene glycol (PEG) commonly used biocompatible molecule due its hydrophilic nature and capacity reduce protein adsorption. Corn trypsin inhibitor (CTI) selective Factor XII, initial factor responsible for activating intrinsic By sequentially applying these two coatings PDMS substrates, we expect PEG-CTI decrease...

Artificial lungs have been used in the clinic for multiple decades to supplement patient pulmonary function. Recently, small-scale microfluidic artificial (μAL) demonstrated with large surface area blood volume ratios, biomimetic flow paths, and pressure drops compatible pumpless operation. Initial devices rates μl/min ml/min range exhibited excellent gas transfer efficiencies; however, current manufacturing techniques may not be suitable scaling up human applications. Here, we present a new...

Microfluidic artificial lungs (μALs) are being researched for future clinical use due to the potential increased gas exchange efficiency, small blood contacting surface area, priming volume, and biomimetic flow paths. However, a current roadblock is need stack hundreds thousands of these small-scale μALs in parallel reach clinically relevant flows. The so many layers not only increases complexity projected cost manufacture μAL, but also could result devices which cumbersome, and, therefore,...

Development and testing of a small-scale 3D printed microfluidic artificial lung (μAL) fabricated via UV light based vat photopolymerization custom polydimethylsiloxane photopolymer resin.

A micro gas chromatograph (μGC) capable of quantitatively analyzing the components complex vapor mixtures at trace concentrations is described. The μGC features a micro- preconcentrator/focuser (μPCF), dual-column pressure- and temperature-programmed separation module, an integrated array nanoparticle-coated chemiresistors. latest design modifications performance data are presented. Highlights include 4-min 30-component mixture with 3-m DRIE Si/glass microcolumn, 14-sec 11-component on 25-cm...

Current hollow fiber membrane lungs feature a predominantly straight blood path length across the bundle, resulting in limited O2 transfer efficiency because of diffusion boundary layer effect. Using computational fluid dynamics and optical flow visualization methods, lung was designed comprising unique concentric circular paths connected by gates. The prototype lung, surface area 0.28 m, has rated 2 L/min, oxygenation is 357 ml/min/m. CO2 clearance 200 ml/min at flow. Given its high gas...

Microfluidics is a rapidly advancing technology with expansive applications but has been restricted by slow, laborious fabrication techniques for polydimethylsiloxane (PDMS)-based devices. Currently, 3D printing promises to address this challenge high-resolution commercial systems limited lack of material advances in generating high-fidelity parts micron-scale features. To overcome limitation, low-viscosity, photopolymerizable PDMS resin was formulated methacrylate-PDMS copolymer, telechelic...

This paper presents a miniature implantable power source that scavenges energy from the expansion and contraction of an artery. The 0.25 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> device consists piezoelectric thin film embedded within flexible, self-curling medical-grade silicone cuff. It is expected to enable self-powered implanted microsystems with near-continuous operation, increased lifetime, reduced surgical replacement,...

Children with end-stage lung failure awaiting transplant would benefit from improvements in artificial technology allowing for wearable pulmonary support as a bridge-to-transplant therapy. In this work, we designed, fabricated, and tested the Pediatric MLung-a dual-inlet hollow fiber based on concentric gating, which has rated flow of 1 L/min, pressure drop 25 mm Hg at flow. This device future iterations current design are designed to relieve arterial hypertension, provide support, reduce...

This paper presents the theory, fabrication, and experimental results for a microfabricated gas chromatography column capable of performing multi-component separations using air as carrier vacuum at outlet. These features are necessary to realization wristwatch-size chromatograph (/spl mu/GC), but pose significant challenges in design high-performance column. Columns 0.9 m 3.0 long were fabricated deep reactive ion etch (DRIE) sealed with glass cap. The m-long non-polar occupies 3.2 cm/spl...