Effect of electrode characteristics on electromyographic activity of the masseter muscle.

OBJECTIVES: The study investigated effects of electrode material, inter-electrode distance (IED), and conductive gel on electromyographic (EMG) activity recorded from the masseter muscle. MATERIALS AND METHODS: EMG was recorded unilaterally, as ten volunteers performed standardized oral tasks. Ag/AgCl and Ag coated with Au were the gel-based; Ag alloy coated with graphene, pure Ag coated with graphene and silver nanowire embedded electrodes were the gel-free materials tested. Ag/AgCl electrodes were tested at three different IEDs (i.e. 15 mm, 20 mm, 25 mm). An electrode relative performance index (ERPI) was defined and calculated for each of the standardized oral tasks that the volunteers performed. ERPI values obtained for the different oral tasks with different electrode materials and IEDs were compared using two-way repeated-measures ANOVA. RESULTS: ERPI values were not significantly influenced by IED. However, for the electrode materials statistically significant differences were found in ERPI values for all oral tasks. Of the gel-free electrode materials tested, pure silver electrodes coated with graphene had the highest ERPI values followed by Ag alloy electrodes coated with graphene and silver nanowire embedded electrodes. CONCLUSIONS: Within the limitations of the study, IED between 15 and 25 mm has a negligible effect on masseter muscle EMG. Graphene coated and silver nanowire embedded electrodes show promise as gel-free alternatives.

BioFET-SIM web interface: implementation and two applications.

We present a web interface which allows us to conveniently set up calculations based on the BioFET-SIM model. With the interface, the signal of a BioFET sensor can be calculated depending on its parameters, as well as the signal dependence on pH. As an illustration, two case studies are presented. In the first case, a generic peptide with opposite charges on both ends is inverted in orientation on a semiconducting nanowire surface leading to a corresponding change in sign of the computed sensitivity of the device. In the second case, the binding of an antibody/antigen complex on the nanowire surface is studied in terms of orientation and analyte/nanowire surface distance. We demonstrate how the BioFET-SIM web interface can aid in the understanding of experimental data and postulate alternative ways of antibody/antigen orientation on the nanowire surface.

Recent patents on fabrication of nanowires.

Nanowires are the building blocks of future nanodevices and thus methods for fabricating nanowires of various materials in various forms are fundamentally important. Although nanowires have been intensively studied, there are only a few methods that showed promising characteristics for practical applications. Here, we intend to review those patents, which enable nanowire growth to be more controllable and feasible for applications. Various methods for fabricating metal, semiconductor and organic nanowires with promising features are reviewed, where some emphasize the characteristics of individual nanowires, others address the uniformity and alignment of an array of nanowires as a whole. The patents for fabricating nanowires of various materials are introduced in the first part. In the second part, the patents to improve crystalline quality, morphology, uniformity of nanowires are introduced. Finally, the patents for growing aligned nanowire arrays and aligning dispersed nanowires are reviewed.