Volume 86, Issue 3, March 2015
Index of content:
- Optics; Atoms and Molecules; Spectroscopy; Photon Detectors
86(2015); http://dx.doi.org/10.1063/1.4911406View Description Hide Description
An exchange system is presented, which allows ultrafast experiments with high excitation rates (1 kHz) on samples with reaction cycles in the range of a few seconds and small sample volumes of about 0.3 ml. The exchange is accomplished using a commercially available cuvette by the combination of a special type of magnetic stirring with transverse translational motion of the sample cuvette.
- Microscopy and Imaging
86(2015); http://dx.doi.org/10.1063/1.4913271View Description Hide Description
We present the design and construction of a versatile, open frame inverted microscope system for wide-field fluorescence and single molecule imaging. The microscope chassis and modular design allow for customization, expansion, and experimental flexibility. We present two components which are included with the microscope which extend its basic capabilities and together create a powerful microscopy system: A Convex Lens-induced Confinement device provides the system with single-molecule imaging capabilities, and a two-color imaging system provides the option of imaging multiple molecular species simultaneously. The flexibility of the open-framed chassis combined with accessible single-molecule, multi-species imaging technology supports a wide range of new measurements in the health, nanotechnology, and materials science research sectors.
- Electronics; Electromagnetic Technology; Microwaves
86(2015); http://dx.doi.org/10.1063/1.4908173View Description Hide Description
Electromagnets that can produce strong rotating magnetic fields at kHz frequencies are potentially very useful to exert rotating force on magnetic nanoparticles as small as few nanometers in size. In this article, the construction of a pulsed high-voltage rotating electromagnet is demonstrated based on a nested Helmholtz coil design. The energy for the coils is provided by two high-voltage discharge capacitors. The triggered spark gaps used in the experiments show sufficient accuracy to achieve the high frequency rotating magnetic field. The measured strength of the rotating magnetic field is 200 mT. This magnetic field is scalable by increasing the number of turns on the coils, by reducing the dimensions of the coils and by increasing the discharge current/voltage of the capacitors.
- General Instruments
Design of a four-degree-of-freedom nano positioner utilizing electromagnetic actuators and flexure mechanisms86(2015); http://dx.doi.org/10.1063/1.4908128View Description Hide Description
Positioning devices are widely used in industrial applications. High precision is a key performance of the positioner and recently high precision positioners for advanced applications are required to satisfy other performances such as larger motion range, nanometer level precision, and multiple degree-of-freedom (DOF) motion within compact size. We propose a new 4-DOF high-precision positioner employing voice coil motors and flexure guides. Millimeter motion range and nano level resolution were achieved simultaneously, utilizing the frictionless characteristic of the voice coil motors and the flexures. The mathematical model describing static and dynamic behaviors of the positioner was developed and the design parameters were optimized to achieve the best performances. The proposed positioner was manufactured with the size of 180 × 180 × 30.7 mm3 which was very compact. The experiment of feedback control showed the motion range more than 1.80 × 1.80 mm2 in-plane and 0.3 mm vertically and the minimum resolution of 10 nm in-plane and 14 nm vertically.