Design and Characterisation of a Non-Contact Flexible Sensor Array for Electric Potential Imaging Applications

Abstract

Capacitive non-contact imaging of electric fields and potentials with micro-metre resolution can provide relevant insights into material characterisation, structural analysis, electrostatic charge imaging and bio-sensing applications. However, scanning electric potential microscopes have been confined to rigid and single-probe devices, making them slow, prone to mechanical damage and complex to fabricate. In this work, we present the design and characterisation of a novel 5-element flexible array of electric potential probes with spatial resolution down to 20 µm to speed up the scanning time. This was achieved by combining flexible thin-film probes for active guarding and shielding with state-of-the art discrete conditioning circuits. The potential of this approach is showcased by using the fabricated array to image latent fingerprints deposited on an insulating surface by contact electrification, obtain the surface topography of conductive samples and to visualise local dielectric variations.

Non-contact thin-film sheet conductance measurement based on the attenuation of low frequency electric potentials

“…The sensing area of the electrometer is 5 µm in diameter. A similar system was previously used to quantify local DC voltage variations [23], and to acquire high fidelity maps of electric potentials [24]. The electrometer is raster scanned at a constant height of 50 µm above the conductive thin-film.…”

Remote monitoring method for human body electrostatic potential based on symbolic regression machine learning

“…In [15,16], Prance invented an electrostatic potential sensor (EPS) with high sensitivity, high accuracy, better stability, and low noise. It was the state-of-the-art discrete conditioning circuit for electrostatic potential measurement [8,17]. Its commercial version is EPIC (Plessey Semiconductors, PS25255) [18].…”