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We have developed a novel process for the microfabrication of atomic force microscope (AFM) cantilevered tips from silicon.on-insulator (SOI) wafers. The tip and cantilever are made of crystalline silicon and low-stress silicon nitride, respectively. This choice of materials allows us to sharpen the tips by oxidation sharpening without affecting the cantilever. We evaluated their performance in contact mode during imaging of artificial nanostructures and compared them to commercially available ones. The images acquired with our tips feature superior resolution on those samples. Index Terms - Atomic force microscope, microfabricated cantilevers, microfabricated tips, silicon-on-insulator wafers. more...

Measurement of adhesion and friction force between probe tips and substrates covalently attached to self-assembled monolayers terminating in distinct functional groups shows that the interaction between COOH/COOH is greater than CH3/CH3 and is greater than COOH/CH3. Experimental results indicate that friction force between different functional groups is related to the adhesion force between the same groups which forms the basis for chemical force microscopy. more...

Au and ITO substrates exposed to equimolar solution of a thiol, and either carboxylic acid or phosphoric acid, led to an orthogonal self-assembly (OSA). It was confirmed by a number of techniques. OSA can be applied to direct the spontaneous assembly of molecular reagents, leading to microelectronics. more...

Electrochemistry, infrared reflectance, and microelectrchemistry have been used to study polyaniline's potential-dependent nucleophilicity. The application of the reversible trifluoroacetylation of polyaniline testifies to a novel approach to an erasable-programmable-read-only-memory instrument, due to changes in conductivity. more...

The reversible redox-active chelating ligand, 1,1'-bis(diphenylphosphino)- cobaltocene acts as an electrochemically-tunable ligand to control the reactivity of an Re(I) carbonyl group during nucleophilic attack in metal carbonyl complexes. Cyclic voltammetry analyzes the redox potential of the ligand. Various spectroscopic methods characterize the products. Ionic and dielectric strengths influence reaction kinetics. more...

Self-assembled monolayers (SAM) of gold with aryl azide and cyclopentadienylmanganese tricarbonyl facilitated the photopatterning of Au surfaces and microstructures at a lateral resolution greater than 2 micrometers. The photochemistry of aryl azides in the amines were applied to aryl azides comprising of thiolate SAMS on Au to yield surface-confined primary photoproducts that resembled products obtained in solutions. more...

Mo or W initiators cyclopolymerize 1,6-heptadiyne derivatives through an 'alkylidene mechanism' which involved the reaction of a triple bond with a M double bond C bond, which produced a metallacyclobutene intermediate that subsequently generated a vinyl alkylidene complex. more...

Microelectrochemical multitransistor devices based on the reversible electrostatic incorporation of electroactive anionic metal complexes, such as IrCl62-, Mo(CN)84-, and Fe(CN)64-, into protonated poly(4-vinylpyridine) ((VPyH+)(sub n)) can detect and differentiate between these species. Arrays of closely spaced, individually addressable, band microelectrodes are connected by (VPyH+)(sub n). Pairs of these microelectrodes are operated as independent microelectrochemical transistors. Each transistor shows high drain current only when its gate potential corresponds to the redox potential of a metal complex bound to the (VPyH+)(sub n), and this serves as the means of detecting and identifying the metal complex. Binding of anionic metal complexes in (VPyH+)(sub n) is reversible, and therefore, the devices can be demonstrated to respond continuously to a flow of electrolyte in which the number and identity of the metal complexes is varied. more...

The self-assembled monolayers (SAMs) of thiol-containing molecules and related isotopic molecules bound to polycrystalline Au films were depicted using secondary ion mass spectrometry (SIMS). The spectra were recorded with the help of a VG IX70S magnetic sector SIMS device with a high lateral resolution imaging ability. more...

Fourier transform infrared spectroscopic study of the photochemistry of ferraazetines in CO-saturated methylcyclohexane showed that the CO and alkyne insertion derivatives from Fe2(CHCHNBu sub t)(CO)6 involved a two-photon process. Furthermore, the unsaturated compounds derived from the Fe-N bond cleavage of the ferraazetines were found to undergo rearrangements either via thermal or photochemical reactions depending on the matrix/solution temperature and pendant group reactivity. In addition, the insertions of CO and tert-butylacetylene respectively occur at the Fe-N and Fe-C bonds of the ferraazetine ring. more...

Describes a photolithographic process for the patterning of WO[sub3]. Illustration of the WO[sub3]-based transistor; Process for selective modification of a microelectrode array with WO[sub3].

The synthesis of electrochemical catalysts is illustrated by microfabrication. The activity of Pt-Sn structures fabricated onto Pt toward the electrochemical Sn and Pt-Sn structures by Auger electron spectroscopy, atomic force microscopy, and scanning electron microscopy is evaluated. more...

Suggests chemistry should be better taught to undergraduates with more emphasis on lifelong learning experience. Emphasizes the collaboration needed between chemistry disciplines. Lists suggestions for curriculum change in chemistry. (ML) more...

Deliberate modification of semiconductor photoelectrodes to improve durability and enhance rate of desirable interfacial redox processes is discussed for a variety of systems. Modification with molecular-based systems or with metals/metal oxides yields results indicating an important role for surface modification in devices for fundamental study and in practical energy conversion. (JN) more...