Chemical electrification at solid/liquid/air interface by surface dipole of self-assembled monolayer and harvesting energy of moving water.

Harvesting energy from water motion is attractive and is considered as a promising component in a microgenerator system for decentralized energy. Recent developments have been shown to rely on spontaneous electrification at the solid-liquid interface, even though the precise mechanism is still under debate. In this paper, we report that the triple-phase boundary of solid/liquid/air can be quantitatively charged by tuning the work function by modifying a self-assembled monolayer (SAM), where a permanent or redox-active dipole controls the polarity and degree of electrification, and by modulating the electrochemical potential of the solution used.

Analysis of the Charging Current in Cyclic Voltammetry and Supercapacitor's Galvanostatic Charging Profile Based on a Constant-Phase Element.

We investigated the charging current in cyclic voltammetry and the galvanostatic charging/discharging behavior of a controversial constant-phase element (CPE) to describe an electrical double layer used only in electrochemical impedance spectroscopy. The linear potential sweep in the time domain was transformed into the frequency domain using a Fourier transform. The current phasor was estimated by Ohm's law with the voltage phasor and a frequency-dependent CPE, followed by an inverse Fourier transform to determine the current in the time domain.

Do-It-Yourself Pyramidal Mold for Nanotechnology.

The handcrafted fabrication of a pyramidal mold on a silicon wafer for nanopatterning was investigated. This process started with the manual delivery of an aqueous glycerol solution onto the SiO/Si wafer using a micropipette and subsequent drying to form a hemisphere whose diameter is in the range of hundreds of micrometers. A coating of polystyrene (PS) onto this wafer generates a circular hole caused by dewetting.

Can Static Electricity on a Conductor Drive a Redox Reaction: Contact Electrification of Au by Polydimethylsiloxane, Charge Inversion in Water, and Redox Reaction.

We investigated the static charge generation by contact electrification between Au and polydimethylsiloxane (PDMS) and the redox reaction by the static charge in the aqueous phase, to reveal the mechanism of contact electrification and redox reaction which may be applied to mechanical-to-chemical energy harvesting. First, the static charge distribution on the equipotential Au was probed through Kelvin probe force microscopy (KPFM) in air after the contact with patterned PDMS. Positive charges are localized on the contact areas indicating the ion migration while the polarity becomes negative after water contact.

A wet-chemistry-based hydrogel sensing platform for 2D imaging of pressure, chemicals and temperature.

Human skin can perceive pressure, chemical compounds and temperature with a high spatial resolution via specific receptors. Inspired by human skin, we present a wet-chemistry based hydrogel sensing platform for 2D imaging sensitive to specific external stimuli, e.g.

H(+)-Assisted fluorescent differentiation of Cu(+) and Cu(2+): effect of Al(3+)-induced acidity on chemical sensing and generation of two novel and independent logic gating pathways.

A novel Schiff base probe exhibited strong 'turn-ON' fluorescence for Cu(2+) at 345 nm, Al(3+) at 445 nm, and Cu(+) at 360 nm in the presence of Al(3+) in organic solvent (acetonitrile), which allowed for construction of molecular logic gates 'INH' and '1:2 DEMULTIPLEXING.' H(+) generated from Al(3+) contributed greatly to Cu(+) chemosensing based on a redox non-innocence mechanism.