Intramolecular force-compensated hydrogel-based sensors with reduced response times

2019 ◽  
Vol 86 (4) ◽  
pp. 227-236 ◽  
Author(s):  
Simon Binder ◽  
Gerald Gerlach
Keyword(s):  
Response Time ◽  
Response Times ◽  
Ion Concentration ◽  
New Approach ◽  
Long Term Stability ◽  
Continuous Sensor ◽  
Successful Reduction ◽  
Force Compensation ◽  
Hysteresis Behaviour

AbstractThe method of intramolecular force compensation forms a new approach for reducing the response time of hydrogel-based chemical sensors and improving their long-term stability. The principle is based on a single bisensitive hydrogel, that fulfills both the function of a sensor and an actuator. This paper presents the measuring principle, the required bisensitive hydrogel and a sensor setup. The results show the desired bisensitivity of the sensor to the temperature and ion concentration as well as the successful reduction of the response time by more than 50 % compared to the conventional deflection method. The continuous sensor operation with the application of varying measuring solvents indicates a negligibly low hysteresis behaviour.

scholarly journals An approach for long-term, multi-probe Neuropixels recordings in unrestrained rats

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Thomas Zhihao Luo ◽  
Adrian Gopnik Bondy ◽  
Diksha Gupta ◽  
Verity Alexander Elliott ◽  
Charles D Kopec ◽  
...  
Keyword(s):  
Cost Effective ◽  
New Approach ◽  
Neural Recordings ◽  
Chronic Recording ◽  
Long Term Stability ◽  
Multiple Cycles ◽  
Single Unit Recordings ◽  
Freely Moving ◽  
High Yields

The use of Neuropixels probes for chronic neural recordings is in its infancy and initial studies leave questions about long-term stability and probe reusability unaddressed. Here, we demonstrate a new approach for chronic Neuropixels recordings over a period of months in freely moving rats. Our approach allows multiple probes per rat and multiple cycles of probe reuse. We found that hundreds of units could be recorded for multiple months, but that yields depended systematically on anatomical position. Explanted probes displayed a small increase in noise compared to unimplanted probes, but this was insufficient to impair future single-unit recordings. We conclude that cost-effective, multi-region, and multi-probe Neuropixels recordings can be carried out with high yields over multiple months in rats or other similarly sized animals. Our methods and observations may facilitate the standardization of chronic recording from Neuropixels probes in freely moving animals.

scholarly journals A new method for continuous measurements of oceanic and atmospheric N<sub>2</sub>O, CO and CO<sub>2</sub>: performance of off-axis integrated cavity output spectroscopy (OA-ICOS) coupled to non-dispersive infrared detection (NDIR)

Ocean Science ◽  
2013 ◽  
Vol 9 (6) ◽  
pp. 1071-1087 ◽  
Author(s):  
D. L. Arévalo-Martínez ◽  
M. Beyer ◽  
M. Krumbholz ◽  
I. Piller ◽  
A. Kock ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Response Times ◽  
Equatorial Atlantic ◽  
Atmospheric Measurements ◽  
Long Term Stability ◽  
Ascension Island ◽  
Cavity Output ◽  
Equatorial Atlantic Ocean ◽  
Equatorial Upwelling

Abstract. A new system for continuous, highly resolved oceanic and atmospheric measurements of N2O, CO and CO2 is described. The system is based upon off-axis integrated cavity output spectroscopy (OA-ICOS) and a non-dispersive infrared analyzer (NDIR), both coupled to a Weiss-type equilibrator. Performance of the combined setup was evaluated by testing its precision, accuracy, long-term stability, linearity and response time. Furthermore, the setup was tested during two oceanographic campaigns in the equatorial Atlantic Ocean in order to explore its potential for autonomous deployment onboard voluntary observing ships (VOS). Improved equilibrator response times for N2O (2.5 min) and CO (45 min) were achieved in comparison to response times from similar chamber designs used by previous studies. High stability of the OA-ICOS analyzer was demonstrated by low optimal integration times of 2 and 4 min for N2O and CO respectively, as well as detection limits of < 40 ppt and precision better than 0.3 ppb Hz–1/2. Results from a direct comparison of the method presented here and well-established discrete methods for oceanic N2O and CO2 measurements showed very good consistency. The favorable agreement between underway atmospheric N2O, CO and CO2 measurements and monthly means at Ascension Island (7.96° S 14.4° W) further suggests a reliable operation of the underway setup in the field. The potential of the system as an improved platform for measurements of trace gases was explored by using continuous N2O and CO2 data to characterize the development of the seasonal equatorial upwelling in the Atlantic Ocean during two R/V Maria S. Merian cruises. A similar record of high-resolution CO measurements was simultaneously obtained, offering, for the first time, the possibility of a comprehensive view of the distribution and emissions of these climate-relevant gases in the area studied. The relatively simple underway N2O/CO/CO2 setup is suitable for long-term deployment onboard research and commercial vessels although potential sources of drift, such as cavity temperature, and further technical improvements towards automation, still need to be addressed.

High performance electrochromic devices based on a polyindole derivative, poly(1H-benzo[g]indole)

2015 ◽  
Vol 3 (43) ◽  
pp. 11318-11325 ◽  
Author(s):  
Guangming Nie ◽  
Ling Wang ◽  
Changlong Liu
Keyword(s):  
Response Time ◽  
High Performance ◽  
Optical Memory ◽  
Fast Response ◽  
Electrochromic Devices ◽  
Optical Contrast ◽  
Fast Response Time ◽  
Coloration Efficiency ◽  
Long Term Stability

An ECD based on electrochromic poly(1H-benzo[g]indole) was fabricated. The color of this ECD can switch between green and navy blue with good optical contrast, high coloration efficiency, fast response time, better optical memory and long-term stability.

One-Step Surgical Correction of Transverse and Anteroposterior Maxillary Deficiencies Using Wire Fixation. A New Approach and Long-Term Stability

2017 ◽  
Vol 75 (7) ◽  
pp. 1498-1513
Author(s):  
Max Domingues Pereira ◽  
Vivian Farfel ◽  
Gabriela Pereira Ribeiro Prado ◽  
Lydia Masako Ferreira
Keyword(s):  
Surgical Correction ◽  
New Approach ◽  
Term Stability ◽  
Long Term Stability ◽  
Wire Fixation ◽  
One Step

scholarly journals An approach for long-term, multi-probe Neuropixels recordings in unrestrained rats

2020 ◽  
Author(s):  
Thomas Zhihao Luo ◽  
Adrian G. Bondy ◽  
Diksha Gupta ◽  
Verity A. Elliott ◽  
Charles D. Kopec ◽  
...  
Keyword(s):  
Cost Effective ◽  
New Approach ◽  
Neural Recordings ◽  
Chronic Recording ◽  
Long Term Stability ◽  
Multiple Cycles ◽  
Single Unit Recordings ◽  
Freely Moving ◽  
High Yields

AbstractThe use of Neuropixels probes for chronic neural recordings is in its infancy and initial studies leave questions about long-term stability and probe reusability unaddressed. Here we demonstrate a new approach for chronic Neuropixels recordings over a period of months in freely moving rats. Our approach allows multiple probes per rat and multiple cycles of probe reuse. We found that hundreds of units could be recorded for multiple months, but that yields depended systematically on anatomical position. Explanted probes displayed a small increase in noise compared to unimplanted probes, but this was insufficient to impair future single-unit recordings. We conclude that cost-effective, multi-region, and multi-probe Neuropixels recordings can be carried out with high yields over multiple months in rats or other similarly sized animals. Our methods and observations may facilitate the standardization of chronic recording from Neuropixels probes in freely moving animals.

New Trim Configurations for Laser Trimmed Thick-Film Resistors – Experimental Verification

2005 ◽  
Vol 2 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Slawomir Kaminski ◽  
Edward Mis ◽  
Maciej Szymendera ◽  
Andrzej Dziedzic
Keyword(s):  
Thick Film ◽  
Experimental Verification ◽  
Electrical Potential ◽  
Low Frequency ◽  
Frequency Noise ◽  
New Approach ◽  
Long Term Stability ◽  
Pathway Length ◽  
Contact Shape

Laser trimming is the most effective and popular trimming method of thick-film and LTCC resistors at present. It is also still a subject of continuing theoretical and experimental analysis and optimization. Very recently a new approach to this process was suggested. It consists in replacing two-contact bar resistors by three-contact distributed structures trimmed by narrow cuts just around additional contact of different shape [1,2]. This paper presents experimental verification of such an approach. The relative trim characteristic and sensitivity are analyzed as a function of additional contact shape and cut length. Next long-term stability, pulse durability and low frequency noise are compared for two- and three-contact resistors versus trim pathway length. These investigations are completed by simulation of electrical potential distribution in two- and three-contact resistors with various length of trimming kerf.

scholarly journals High Sensitivity Flexible Electronic Skin Based on Graphene Film

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 794 ◽  
Author(s):  
Xiaozhou Lü ◽  
Jiayi Yang ◽  
Liang Qi ◽  
Weimin Bao ◽  
Liang Zhao ◽  
...  
Keyword(s):  
Response Time ◽  
Graphene Film ◽  
High Sensitivity ◽  
Middle Layer ◽  
Fast Response ◽  
Long Term Stability ◽  
Electronic Skin ◽  
Flexible Electronic ◽  
Object Based

Electronic skin with high sensitivity, rapid response, and long-term stability has great value in robotics, biomedicine, and in other fields. However, electronic skin still has challenges in terms of sensitivity and response time. In order to solve this problem, flexible electronic skin with high sensitivity and the fast response was proposed, based on piezoresistive graphene films. The electronic skin was a pressure sensor array, composed of a 4 × 4 tactile sensing unit. Each sensing unit contained three layers: The underlying substrate (polyimide substrate), the middle layer (graphene/polyethylene terephthalate film), and the upper substrate bump (polydimethylsiloxane). The results of the measurement and analysis experiments, designed in this paper, indicated that the flexible electronic skin achieved a positive resistance characteristic in the range of 0 kPa–600 kPa, a sensitivity of 10.80 Ω /kPa in the range of 0 kPa–4 kPa, a loading response time of 10 ms, and a spatial resolution of 5 mm. In addition, the electronic skin realized shape detection on a regular-shaped object, based on the change in the resistance value of each unit. The high sensitivity flexible electronic skin designed in this paper has important application prospects in medical diagnosis, artificial intelligence, and other fields.

Photo- and electro-chemical processes at organic crystal electrodes. I. Chronophotometry: a technique to study processes at electrodes

1976 ◽  
Vol 29 (1) ◽  
pp. 13
Author(s):  
KG McGregor
Keyword(s):  
Response Time ◽  
Chemical Processes ◽  
Organic Crystal ◽  
Term Stability ◽  
Long Term Stability ◽  
Electrochemical Processes ◽  
Absorbance Changes

A 'chronophotometer' is described in this, the first of a series of connected papers. It measures, at a selected wavelength, absorbance changes with a resolution of 4 x 106 and a response time of 0.1s. It is suitable for following species with suitable absorption peaks generated by chemical or electrochemical processes in amounts as low as The long-term stability of the instrument allows these processes to be monitored after sufficiently long periods have elapsed for detectable absorbance to occur. The chronophotometer is used in following papers on electrochemical processes at organic crystal electrodes.

scholarly journals Monitoring the State of Charge of the Positive Electrolyte in a Vanadium Redox-Flow Battery with a Novel Amperometric Sensor

Batteries ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 5 ◽  
Author(s):  
Isabelle Kroner ◽  
Maik Becker ◽  
Thomas Turek
Keyword(s):  
Gas Diffusion ◽  
The State ◽  
State Of Charge ◽  
Vanadium Redox Flow Battery ◽  
Rotating Disc ◽  
New Approach ◽  
Long Term Stability ◽  
The Individual ◽  
Vanadium Redox

Vanadium redox-flow batteries are a promising energy storage technology due to their safety, long-term stability, and independent adjustability of power and capacity. However, the vanadium crossover through the membrane causes a self-discharge, which results in a capacity shift towards one half cell. This leads to a gradual decrease in its efficiency over time. Capacity balancing methods for compensation of this effect require a reliable online state of charge (SoC) monitoring. Most common methods cannot provide exact values of the individual concentration of each species in both electrolytes. In particular, the state of the positive electrolyte cannot yet be precisely determined. In this work, an amperometric SoC monitoring is proposed as a new approach. First, the suitability of the principle is investigated with a rotating disc electrode (RDE). Then, a sensor based on a gas diffusion layer (GDL) is developed and tested in the positive electrolyte. The dependencies between oxidative current and V(IV)-concentration are examined as well as those between reduction current and V(V)-concentration. Using both relationships, a reliable measurement of all relevant concentrations is possible.

scholarly journals Rapid Method for Isolation of Desiccation-Tolerant Strains and Xeroprotectants

2010 ◽  
Vol 76 (15) ◽  
pp. 5254-5262 ◽  
Author(s):  
J. J. Narv�ez-Reinaldo ◽  
I. Barba ◽  
J. Gonz�lez-L�pez ◽  
A. Tunnacliffe ◽  
M. Manzanera
Keyword(s):  
Compatible Solutes ◽  
Soil Samples ◽  
Environmental Implications ◽  
Air Drying ◽  
New Approach ◽  
Long Term Stability ◽  
Therapeutic Value ◽  
Natural Isolates ◽  
Incubation Method

ABSTRACT A novel biotechnological process has been developed for the isolation of desiccation-tolerant microorganisms and their xeroprotectants, i.e., compatible solutes involved in long-term stability of biomolecules in the dry state. Following exposure of soil samples to chloroform, we isolated a collection of desiccation-tolerant microorganisms. This collection was screened for the production of xeroprotectants by a variation of the bacterial milking (osmotic downshock) procedure and by a novel air-drying/rehydration (“dry milking”) incubation method. The resultant solutes were shown to protect both proteins and living cells against desiccation damage, thereby validating them as xeroprotectants. Nuclear magnetic resonance (NMR) analytical studies were performed to identify the xeroprotectants; synthetic mixtures of these compounds were shown to perform similarly to natural isolates in drying experiments with proteins and cells. This new approach has biotechnological and environmental implications for the identification of new xeroprotectants of commercial and therapeutic value.

Sign in / Sign up

Export Citation Format

Share Document