Multitip scanning bio-Kelvin probe

Abstract

We have developed a novel multitip scanning Kelvin probe which can measure changes in biological surface potential ΔVs to within 2 mV and, quasisimultaneously monitor displacement to <1 μm. The control and measurement subcomponents are PC based and incorporate a flexible user interface permitting software control of each individual tip, measurement, and scan parameters. We review the mode of operation and design features of the scanning bio-Kelvin probe including tip steering, signal processing, tip calibration, and novel tip tracking/dithering routines. This system uniquely offers both tip-to-sample spacing control (which is essential to avoid spurious changes in ΔVs due to variations in mean spacing) and a dithering routine to maintain tip orientation to the biological specimen, irrespective of the latter’s movement. These features permit long term (>48 h) “active” tracking of the displacement and biopotentials developed along and around a plant shoot in response to an environmental stimulus, e.g., differential illumination (phototropism) or changes in orientation (gravitropism).

Work function studies of rare-gas/noble metal adsorption systems using a Kelvin probe

“…When investigating metal surfaces an important material-dependent parameter is the work function ⌽, being very sensitive to crystallographic orientation, surface structure, and impurities. [1][2][3][4] Efforts in molecular electronics can only be successful if the molecule/metal interface is understood in detail. 5 Therefore the understanding of kinetics and topography of adsorbate systems [6][7][8] are of considerable significance.…”

Ether solvent treatment to improve the device performance of the organic light emitting diodes with aluminum cathode

“…Second, the residual ether reacts with aluminum during the metal deposition, and the product contributes to the efficient electron injection [23][24][25][26][27][28]. Kelvin Probe was used to measure the surface potential of the P-PPV film before and after EE treatment to detect if a dipole layer was formed by the ether solvent molecules [29,30]. Before EE treatment, the contact potential difference (CPD) between the KP tip and the P-PPV surface is 0.47 V. After EE treatment, the CPD becomes 0.55 V. The difference of 0.08 V shows that a weak dipole layer is formed by the ether solvent on the P-PPV film surface.…”

Multidimensional electrochemical imaging in materials science

“…1b). Several reviews and research articles during the last two decades show KFM has been applied in biological research [30][31][32], studies at polymer-metal interfaces [33][34][35], and, especially, in corrosion science [36][37][38][39][40][41][42][43]. Scanning electrochemical microscopy (SECM) complements STM and C-AFM because it probes interfacial processes (chemical reactions at liquid-gas, liquid-liquid, and liquid-solid interfaces) with high spatial resolution and well-characterized mass transport [44,45] (Fig.…”