Molybdenum-rhenium (Mo/Re) and tungsten-rhenium (W/Re) alloys were investigated as substrates for

Molybdenum-rhenium (Mo/Re) and tungsten-rhenium (W/Re) alloys were investigated as substrates for thin-film polycrystalline boron-doped diamond electrodes. diamond films on the alloys displayed grain sizes and Raman signatures similar to films grown on tungsten; in all cases the morphology and Raman spectra were consistent with well-faceted microcrystalline diamond with minimal sp2 carbon content. Cyclic voltammograms of dopamine in phosphate-buffered saline Clavulanic acid (PBS) showed the wide window and low baseline current of high-quality diamond electrodes. In addition the films showed consistently well-defined dopamine electrochemical redox activity. The Mo/Re substrate regions that were uncoated but still exposed to the diamond-growth environment remained substantially more flexible than tungsten in a bend-to-fracture rotation test bending to the test maximum of 90° and not fracturing. The W/Re substrates fractured after a 27° Clavulanic acid bend and the tungsten fractured after a 21° bend. Brittle transgranular cleavage fracture surfaces were observed for tungsten and W/Re. A tension-induced fracture from the Mo/Re following the prior flex check demonstrated a dimple fracture with a visible ductile core. Overall the Mo/Re and W/Re alloys were Clavulanic acid suitable substrates for diamond growth. The Mo/Re alloy remained significantly more ductile than traditional tungsten substrates after diamond growth and thus may be an attractive metal substrate for more ductile thin-film diamond electrodes. 1 Introduction Although carbon thin films containing diamond graphene or carbon nanotubes have promising engineering properties a limiting factor in the processing of carbon films is identifying appropriate substrates for film fabrication [1-9]. For example diamond films grow conformally on high-temperature materials that pre-form a carbide interfacial layer to enhance film adhesion (tissue in a dish)[7 21 22 or (implantation in a live animal) [1 23 has brought renewed attention to the need for alternatives to traditional high-temperature substrates. Both the coated and uncoated Clavulanic acid regions of tungsten and molybdenum become brittle during diamond chemical vapor deposition (CVD) (1000°C hydrogen/methane environment) due to the carbide Rabbit polyclonal to ADNP. formation and hydrogen incorporation [2 3 9 16 The brittle substrates fracture when a bending stress is applied thereby preventing their use in long-term biomedical implants that must conform to tissue movement. Conductive diamond has potential advantages in biodevice applications testing in intact behaving animals such that the diamond electrode structure is usually flexible yet maintains performance and mechanical integrity Clavulanic acid for weeks or months. Recently developed diamond electrode sensor prototypes suitable for preparations were reviewed by Park in 2008 [7]; yet use were diamond-on-platinum and diamond-on-tungsten wire-based sensors constructed by purposely cutting the wire after diamond growth to attach a flexible electrical lead [3 23 27 and device assembly with hand-made junctions that produces multiple sites for device failure. With regard to fabrication Clavulanic acid of planar devices a first-generation all-diamond flexible device with an integrated electrode and lead was reported [1]. The flexibility of the all-diamond gadget was due to a slim ultrananocrystalline gemstone coating because the electrode however the gadget exhibited a minimal signal-to-noise proportion of 2 during severe electrical documenting [1]. Diamond-on-polymer versatile arrays also present potential but haven’t yet been examined [28 29 History work provides proof that substitute substrates and modification of development conditions are essential to improve the flexibleness from the development substrate while preserving the gemstone film quality. Faceted high-quality consistent gemstone films have already been expanded on rhenium that includes a equivalent crystal structure to many carbides [10 30 The rhenium substrate continued to be ductile after gemstone coating likely partly because of too little carbide development [31-33] however the gemstone film easily delaminated [34]. Within this record we investigate rhenium alloyed with a normal carbide-forming steel (tissue planning; the resulting gemstone wire electrodes had been characterized utilizing a bend-to-fracture rotation check checking electron microscopy (SEM) microRaman spectroscopy and cyclic.