We report a simple method of preparation of carbon paste ultramicroelectrodes (UMEs) for use as probe tips in scanning electrochemical microscopy (SECM). Carbon paste UMEs were prepared by packing the carbon paste into a chemically etched tip of a Pt-UME or a pulled glass capillary. Carbon-based UMEs are attractive in micrometer to nanometer gap experiments and in electrodeposition of single me...

Optical antennas are of fundamental importance for the strongly localizing field beyond the diffraction limit. We report that planar optical antennas made of split-ring architecture are numerically found in three-dimensional simulations to outperform dipole antennas for the enhancement of localized field intensity inside their gap regions. The computational results (finite-difference time-domai...

We report on the set-up and performance of a dilution-refrigerator based spectroscopic imaging scanning tunneling microscope. It operates at temperatures below 10 mK and in magnetic fields up to 14T. The system allows for sample transfer and in situ cleavage. We present first-results demonstrating atomic resolution and the multi-gap structure of the superconducting gap of NbSe(2) at base temper...

BACKGROUND Angular stable plate fixation is a widely accepted treatment option for interprosthetic or periprosthetic femoral fractures with stable implants. This biomechanical study tries to establish a safe distance of the plate from the tip of a femoral prosthesis. METHODS A total of 38 composite femurs were reamed to an inner diameter of 23 mm to create an osteoporotic bone model. A Weber ...

Hot spots with a large electric field enhancement usually come in small volumes, limiting their applications in surface-enhanced spectroscopy. Using a finite-difference time-domain method, we demonstrate that spiky nanoparticle dimers (SNPD) can provide hot spots with both large electric field enhancement and large volumes because of the pronounced lightning rod effect of spiky nanoparticles. W...

We studied transfer and propagation of excitons in single semiconducting carbon nanotubes using high resolution tip-enhanced near-field photoluminescence microscopy. Exciton energy transfer is found to occur from a larger band gap nanotube to a smaller band gap nanotube. Efficient transfer however is found to be limited to a few nanometers because of competing fast non-radiative relaxation and ...

The selective deposition of compound semiconductors on single crystal silicon tip arrays produces optical quality, direct band gap materials on the silicon nanostructures. We demonstrate using the organometallic vapor phase epitaxy of GaInP that the direct band gap semiconductor nucleates selectively on the silicon tips. The structural properties of the tips ~whose radius of curvature is approx...

We report measurements on the radial electromechanical properties of single walled carbon nanotubes. By measuring the conductance of the nanotube, we show that a gap is opened while squashing the nanotubes and that during the deformation stages we observe at least two open-close cycles of the gap. We employ a novel experimental setup where an atomic force microscope tip is used both as an elect...

Background: The technique of vertical dome division or tip defining, involves incising the lateral crura and vestibular skin at or lateral to the dome or tip defining point. The incision di-vides the lower lateral cartilage into a lateral segment and a medial segment, which are advanced anteriorly and sutured together to increase tip projection. The present study aimed at assessing a new vertic...