A 64-channel, 1.1-pA-accurate on-chip potentiostat for parallel electrochemical monitoring

Electrochemical monitoring is crucial for both industrial applications, such as microbial electrolysis and corrosion monitoring as well as consumer applications such as personal health monitoring. Yet, state-of-the-art integrated potentiostat monitoring devices have few parallel channels with limited flexibility due to their channel architecture. This work presents a novel, widely scalable channel architecture using a switch capacitor based Howland current pump and a digital potential controller. An integrated, 64-channel CMOS potentiostat array has been fabricated. Each individual channel has a dynamic current range of 120dB with 1.1pA precision with up to 100kHz bandwidth. The on-chip working electrodes are post-processed with gold to ensure (bio)electrochemical compatibility

Minimization of Ionic Transport Resistance in Porous Monoliths for Application in Integrated Solar Water Splitting Devices

Monolithic solar water splitting devices consist of photovoltaic materials integrated with electrocatalysts and produce solar hydrogen by water splitting upon solar illumination in one device. Upscaling of monolithic solar water splitting devices is obstructed by high ohmic losses in the electrolyte due to long ionic transport distances. A new design overcomes the problem by introducing micron sized pores in a silicon wafer substrate coated with electrocatalysts. A porous solar hydrogen device was simulated by applying a current corresponding to ca. 10% solar-to-hydrogen efficiency. Porous monoliths of 550 µm thickness with varying pore size and spacing were fabricated by laser ablation and electrochemically characterized. Ohmic losses well below 100 mV were reached at 14.4% porosity with 77 µm pores spaced 250 µm apart in 0.25 M KOH electrolyte. In 1 M KOH, 100 mV was reached at 6% porosity with 1 mm pore spacing. Our results suggest ohmic losses below 50 mV can be achieved when using 10 µm thick substrates at 0.2% porosity. These findings make it possible for monolithic solar water splitting devices to be scaled without loss of efficiency

Integrated Sensors and Actuators: Their Nano-Enabled Evolution into the Twenty-First Century

© 2017 Wiley-VCH Verlag GmbH & Co.KGaA. All rights reserved. This chapter presents how micro- and nanoelectronic fabrication technology influenced the world of transducers. Membrane-based pressure sensors were the ffirst sensors to be miniaturized in silicon. Gas sensors are applied in industrial safety devices, but are reaching the home in applications such as CO detection. All current commercial pressure sensors are still of the membrane type, and also the related microelectromechanical systems (MEMS) microphones are membrane based. A microelectromechanical resonator is an actuated structure that is tuned to vibrate at a certain frequency. There is a great potential for millimeter wave or terahertz imaging to replace or complement a series of nuclear technology-based measuring techniques, such as film thickness monitoring in industry, X-ray scanning, and so on. The increasing performance of nanoelectronics also has its consequences for existing radar and lidar applications. Electrostatic actuation is widely used in microdevices. Piezoelectric actuation is another workhorse at the micro- and nanometer scale.status: publishe

Deep etching of glass wafers using sputtered molybdenum masks

This note presents a simple, low-cost technology to fabricate very deep isotropically etched features in glass wafers. A process based on fast etching glass combined with a stress-optimized molybdenum mask layer and a photoresist was found to be very suitable for such purposes. The obtained performance, up to 1.2 mm deep etching, rivals the best existing techniques while being more cost-competitive and using widely available equipment.status: publishe

Absolute fiber-optic pressure sensing for high-temperature applications using white light interferometry

Fiber-optic pressure sensors allow rugged high-temperature and ultra-miniature pressure monitoring in harsh environments. However, simple light power based readout suffers from bending losses and light source fluctuations. This paper presents a differential technique based on white light interferometry to alleviate this problem. White light spectroscopic measurements have been performed on absolute Fabry-Pérot pressure sensors fabricated at the tip of multi-mode and single mode optical fibers. Bending loss sensitivity is demonstrated to be reduced with a factor of 79% by using the proposed differential spectroscopic technique. © 2013 IEEE.status: publishe

Polymer-CMOS Hybrid Neural Probes for Large-Scale Neuro-Electronic Interfacing

Achieving a stable, long-term connection with millions of neurons within living organisms remains one of the dreams of neuroscience. Silicon shank based probes lead the field in terms of pure channel count. On the other hand, polymer neural probes offer superior biocompatibility, ruggedness and lower cost. This work tries to merge these technologies while exploring new electronic and interconnect design methods, ultimately yielding a prototype of a polymer-CMOS hybrid neural probe with a gold bump interconnect along with an electronic design based on bipolar transistor input devices, pseudo-capacitive AC coupling and in-pixel digitization

Fission thrust sail as booster for high Δv fusion based propulsion

The fission thrust sail as booster for nuclear fusion-based rocket propulsion for future starships is introduced and studied. First order calculations are used together with Monte Carlo simulations to assess system performance. If a D-D fusion rocket such as e.g. considered in Project Icarus has relatively low efficiency (~30%) in converting fusion fuel to a directed exhaust, adding a fission sail is shown to be beneficial for the obtainable delta-v. Additionally, this type of fission-fusion hybrid propulsion has the potential to improve acceleration and act as a micrometeorite shield.publisher: Elsevier articletitle: Fission thrust sail as booster for high Δv fusion based propulsion journaltitle: Acta Astronautica articlelink: http://dx.doi.org/10.1016/j.actaastro.2015.07.032 content_type: article copyright: Copyright © 2015 IAA. Published by Elsevier Ltd. All rights reserved.status: publishe