MM-Wave Metamaterial Adjustable Antenna on Magnetically Biased Ferritic Substrate

The paper presents a mm-wave metamaterial coplanar waveguide (CPW) zeroth-order resonating (ZOR) antenna on magnetically biased ferrite substrate. The measurements demonstrate tuning of the resonant frequency and steering of the radiation characteristic depending on the strength of biasing magnetic field. The resonant frequency shifts about 1.1 GHz for magnetic biasing field strength variation between 0 T and 0.265 T. The return loss is reduced as result of elimination of ferrite low field loss. The radiation characteristic in transversal plane steers between approximately −15° and +14° depending on the magnetic field strength. In the magnetically unbiased state the antenna gain is 4.16 dBi and increases slightly to 4.22 dBi due to small field loss reduction following the magnetic polarization application

Design, Fabrication and Characterization of a Low-Impedance 3D Electrode Array System for Neuro-Electrophysiology

Recent progress in patterned microelectrode manufacturing technology and microfluidics has opened the way to a large variety of cellular and molecular biosensor-based applications. In this extremely diverse and rapidly expanding landscape, silicon-based technologies occupy a special position, given their statute of mature, consolidated, and highly accessible areas of development. Within the present work we report microfabrication procedures and workflows for 3D patterned gold-plated microelectrode arrays (MEA) of different shapes (pyramidal, conical and high aspect ratio), and we provide a detailed characterization of their physical features during all the fabrication steps to have in the end a reliable technology. Moreover, the electrical performances of MEA silicon chips mounted on standardized connector boards via ultrasound wire-bonding have been tested using non-destructive electrochemical methods: linear sweep and cyclic voltammetry, impedance spectroscopy. Further, an experimental recording chamber package suitable for in vitro electrophysiology experiments has been realized using custom-design electronics for electrical stimulus delivery and local field potential recording, included in a complete electrophysiology setup, and the experimental structures have been tested on newborn rat hippocampal slices, yielding similar performance compared to commercially available MEA equipments