158 research outputs found
Direct laser printing of thin-film polyaniline devices
We report the fabrication of electrically functional polyaniline thin-film
microdevices. Polyaniline films were printed in the solid phase by Laser
Induced Forward Transfer directly between Au electrodes on a Si/SiO2 substrate.
To apply solid-phase deposition, aniline was in situ polymerized on quartz
substrates. Laser deposition preserves the morphology of the films and delivers
sharp features with controllable dimensions. The electrical characteristics of
printed polyaniline present ohmic behavior, allowing for electroactive
applications. Results on gas sensing of ammonia are presented.Comment: In Pres
Optical tweezers with enhanced efficiency based on laser-structured substrates
We present an optical nanotrapping setup that exhibits enhanced efficiency,
based on localized plasmonic fields around sharp metallic features. The
substrates consist of laser-structured silicon wafers with quasi-ordered
microspikes on the surface, coated with a thin silver layer. The resulting
optical traps show orders of magnitude enhancement of the trapping force and
the effective quality factor
Phosphate modified screen printed electrodes by lift treatment for glucose detection
The design of new materials as active layers is important for electrochemical sensor and biosensor development. Among the techniques for the modification and functionalization of electrodes, the laser induced forward transfer (LIFT) has emerged as a powerful physisorption method for the deposition of various materials (even labile materials like enzymes) that results in intimate and stable contact with target surface. In this work, Pt, Au, and glassy carbon screen printed electrodes (SPEs) treated by LIFT with phosphate buffer have been characterized by scanning electron microscopy and atomic force microscopy to reveal a flattening effect of all surfaces. The electrochemical characterization by cyclic voltammetry shows significant differences depending on the electrode material. The electroactivity of Au is reduced while that of glassy carbon and Pt is greatly enhanced. In particular, the electrochemical behavior of a phosphate LIFT treated Pt showed a marked enrichment of hydrogen adsorbed layer, suggesting an elevated electrocatalytic activity towards glucose oxidation. When Pt electrodes modified in this way were used as an effective glucose sensor, a 1–10 mM linear response and a 10 µM detection limit were obtained. A possible role of phosphate that was securely immobilized on a Pt surface, as evidenced by XPS analysis, enhancing the glucose electrooxidation is discussed
- …