DC voltage calibrator based on an array of high-temperature superconductor josephson junctions

Клушин, А.М.; Komkov, A.V.; Gelikonova, V.D.; Borovitskii, S. I.; Siegel, M.

doi:10.1109/tim.2003.811581

Cited by 7 publications

(1 citation statement)

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“…At first glance, an increase in the number of thermopile junctions through feature size reduction would seem to benefit P min by increasing S tot ; however, any benefit is equally offset by an increase in noise. With the best amplifiers typically contributing at least 5 nV/(Hz) 1/2 noise, 19 it provides little benefit to reduce V n past that level. It is more advantageous to keep V n around 10À15 nV/(Hz) 1/2 so that 4) determined with acidÀbase neutralizations.…”

Section: ' Results and Discussionmentioning

confidence: 99%

Isothermal Titration Calorimetry in Nanoliter Droplets with Subsecond Time Constants

Lubbers

Baudenbacher

2011

Anal. Chem.

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We reduced the reaction volume in microfabricated suspended-membrane titration calorimeters to nanoliter droplets and improved the sensitivities to below a nanowatt with time constants of around 100ms, The device performance was characterized using exothermic acid-base neutralizations and a detailed numerical model. The finite element based numerical model allowed us to determine the sensitivities within 1% and the temporal dynamics of the temperature rise in neutralization reactions as a function of droplet size. The model was used to determine the optimum calorimeter design (membrane size and thickness, junction area, and thermopile thickness) and sensitivities for sample volumes of 1 nl for silicon nitride and polymer membranes. We obtained a maximum sensitivity of 153 pW/√Hz for a 1 μm SiN membrane and 79 pW/√Hz for a 1 μm polymer membrane. The time constant of the calorimeter system was determined experimentally by using a pulsed laser to increase the temperature of nanoliter sample volumes. For a 2.5 nanoliter sample volume, we experimentally determined a noise equivalent power of 500 pW/√Hz and a 1/e time constant of 110ms for a modified commercially available infrared sensor with a thin-film thermopile. Furthermore, we demonstrated detection of 1.4 nJ reaction energies from injection of 25 pl of 1 mM HCl into a 2.5 nl droplet of 1 mM NaOH.

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Section: ' Results and Discussionmentioning

confidence: 99%