This paper illustrates the characterization of a fabric resistance temperature (RTD) detector made from electrospun nylon-6 functionalized with multiwalled carbon nanotubes (MWCNTs) and polypyrrole (PPy) for use in supracutaneous applications like smart clothing, prosthetic sockets, and other medical devices where a temperature detecting fabric is better suited than a rigid detector. The nanocomposite material acts like a RTD, because the conductivity increases linearly with temperature. The empirically determined temperature coefficient of resistance (TCR) is reported for this material, and is -0.204 ± 0.008%/C. Development of a simple and scalable process for constructing the detector utilized electrospinning nylon-6 as a membrane style substrate, vacuum filtration of MWCNTs onto the nylon scaffold, and vapor phase polymerization of pyrrole to PPy onto the MWCNT functionalized nylon nanofibers. The optimal loading of MWCNTs is 6.6 wt%. The conductivity of the device follows a percolative behavior and TCR values indicate this is a viable option for temperature detection. Resistance decreases with increasing temperature, which indicates this is a negative TCR material.

Implantable sensors utilizing nanotechnology are at the forefront of diagnostic, medical monitoring, and biological technologies. These sensors are often equipped with nanostructured carbon allotropes, such as graphene or carbon nanotubes (CNTs), because of their unique and often enhanced properties over forms of bulk carbon, such as diamond or graphite. Because of these properties, the fundamental and applied research of these carbon nanomaterials have become some of the most cited topics in scientific literature in the past decades. The age of carbon nanomaterials is simply budding, however, and is expected to have a major impact in many areas. These areas include electronics, photonics, plasmonics, energy capture (including batteries, fuel cells, and photovoltaics), and--the emphasis of this review--biosensors and sensor technologies. The following review will discuss future prospects of the two most commonly used carbon allotropes in implantable sensors for nanomedicine and nanobiotechnology, CNTs and graphene. Sufficient further reading and resources have been provided for more in-depth and specific reading that is outside the scope of this general review.

Microbially induced corrosion (MIC) is a complex problem that affects various industries. Several techniques have been developed to monitor corrosion and elucidate corrosion mechanisms, including microbiological processes that induce metal deterioration. We used zero resistance ammetry (ZRA) in a split chamber configuration to evaluate the effects of the facultatively anaerobic Fe(III) reducing bacterium Shewanella oneidensis MR-1 on the corrosion of UNS G10180 carbon steel. We show that activities of S. oneidensis inhibit corrosion of steel with which that organism has direct contact. However, when a carbon steel coupon in contact with S. oneidensis was electrically connected to a second coupon that was free of biofilm (in separate chambers of the split chamber assembly), ZRA-based measurements indicated that current moved from the S. oneidensis-containing chamber to the cell-free chamber. This electron transfer enhanced the O2 reduction reaction on the coupon deployed in the cell free chamber, and consequently, enhanced oxidation and corrosion of that electrode. Our results illustrate a novel mechanism for MIC in cases where metal surfaces are heterogeneously covered by biofilms.

Despite observations of steel corrosion in nitrate-reducing environments, processes of nitrate-dependent microbially influenced corrosion (MIC) remain poorly understood and difficult to identify. We evaluated carbon steel corrosion by MR-1 under nitrate-reducing conditions using a split-chamber/zero-resistance ammetry (ZRA) technique. This approach entails the deployment of two metal (carbon steel 1018 in this case) electrodes into separate chambers of an electrochemical split-chamber unit, where the microbiology or chemistry of the chambers can be manipulated. This approach mimics the conditions of heterogeneous metal coverage that can lead to uniform and pitting corrosion. The current between working electrode 1 (WE1) and WE2 can be used to determine rates, mechanisms, and, we now show, extents of corrosion. When was incubated in the WE1 chamber with lactate under nitrate-reducing conditions, nitrite transiently accumulated, and electron transfer from WE2 to WE1 occurred as long as nitrite was present. Nitrite in the WE1 chamber (without ) induced electron transfer in the same direction, indicating that nitrite cathodically protected WE1 and accelerated the corrosion of WE2. When was incubated in the WE1 chamber without an electron donor, nitrate reduction proceeded, and electron transfer from WE2 to WE1 also occurred, indicating that the microorganism could use the carbon steel electrode as an electron donor for nitrate reduction. Our results indicate that under nitrate-reducing conditions, uniform and pitting carbon steel corrosion can occur due to nitrite accumulation and the use of steel-Fe(0) as an electron donor, but conditions of sustained nitrite accumulation can lead to more-aggressive corrosive conditions. Microbially influenced corrosion (MIC) causes damage to metals and metal alloys that is estimated to cost over $100 million/year in the United States for prevention, mitigation, and repair. While MIC occurs in a variety of settings and by a variety of organisms, the mechanisms by which microorganisms cause this damage remain unclear. Steel pipe and equipment may be exposed to nitrate, especially in oil and gas production, where this compound is used for corrosion and "souring" control. In this paper, we show uniform and pitting MIC under nitrate-reducing conditions and that a major mechanism by which it occurs is via the heterogeneous cathodic protection of metal surfaces by nitrite as well as by the microbial oxidation of steel-Fe(0).

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