9 research outputs found
Enhanced Transmission in Rolled-up Hyperlenses utilizing Fabry-Pe\'rot Resonances
We experimentally demonstrate that the transmission though rolled-up
metal/semiconductor hyperlenses can be enhanced at desired frequencies
utilizing Fabry-P\'erot resonances. By means of finite difference time domain
simulations we prove that hyperlensing occurs at frequencies of high
transmission.Comment: 3 pages, 3 figure
Gain in Three-Dimensional Metamaterials utilizing Semiconductor Quantum Structures
We demonstrate gain in a three-dimensional metal/semiconductor metamaterial
by the integration of optically active semiconductor quantum structures. The
rolling-up of a metallic structure on top of strained semiconductor layers
containing a quantum well allows us to achieve a three-dimensional superlattice
consisting of alternating layers of lossy metallic and amplifying gain
material. We show that the transmission through the superlattice can be
enhanced by exciting the quantum well optically under both pulsed or continuous
wave excitation. This points out that our structures can be used as a starting
point for arbitrary three-dimensional metamaterials including gain
Guided Neuronal Growth on Arrays of Biofunctionalized GaAs/InGaAs Semiconductor Microtubes
We demonstrate embedded growth of cortical mouse neurons in dense arrays of
semiconductor microtubes. The microtubes, fabricated from a strained
GaAs/InGaAs heterostructure, guide axon growth through them and enable
electrical and optical probing of propagating action potentials. The coaxial
nature of the microtubes -- similar to myelin -- is expected to enhance the
signal transduction along the axon. We present a technique of suppressing
arsenic toxicity and prove the success of this technique by overgrowing
neuronal mouse cells.Comment: 3 pages, 4 figure
Culturing and patch clamping of Jurkat T cells and neurons on Al 2 O 3 coated nanowire arrays of altered morphology
Nanowire substrates play an increasingly important role for cell cultures as an approach for hybrid bio-semiconductor junctions. We investigate Jurkat T cells and neurons from mice cultured on Al 2 O 3 coated ordered and randomly distributed nanowires. Cell viability was examined by life/membrane staining reporting comparable viability on planar and nanowire substrates. Imaging the hybrid interface reveals a wrapping of the cell membrane around the very nanowire tip. Patch clamp recordings show similar electrophysiological responses on each type of nanowires compared to planar control substrates. We demonstrate that the morphological characteristic of the nanowire substrate plays a subordinate role which opens up the arena for a large range of nanowire substrates in a functionalized application such as stimulation or sensing