Manufacture, observation, and test of membranes with locatable single pores

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Journal Title
Journal ISSN
Volume Title
School of Science | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
1986
Major/Subject
Mcode
Degree programme
Language
en
Pages
1654-1660
Series
Review of Scientific Instruments, Volume 57, Issue 8
Abstract
A method for generating single pores down to 0.1 μm diameter in the center of a large circular foil is described, based on nuclear tracks. The foil is framed by a tension ring which enables one to handle the foils in a well‐defined precise way. The single pore has a lateral displacement of ±0.1 mm with respect to the tension ring center. The foils used are polycarbonate of the type Makrofol and have thicknesses between 2 and 10 μm. For calibration of the single pore diameters, multiple nuclear tracks between 0.1 and 3.5 μm diameter are etched and observed by microscopy. The microscopic observations are compared with gas‐flow measurements, using two alternative methods: multiple holes are tested under viscous flow conditions of N2 gas at normal temperature and pressure; single holes are tested under collisionless flow conditions of 4He gas at liquid‐nitrogen temperature, using a capacitance method.
Description
Keywords
gas liquid flows, calibration, capacitance, etching, helium-4
Other note
Citation
Packard, R. E. & Pekola, Jukka & Price, P. B. & Spohr, R. N. R. & Westmacott, K. H. & Yu-Qun, Zhu. 1986. Manufacture, observation, and test of membranes with locatable single pores. Review of Scientific Instruments. Volume 57, Issue 8. 1654-1660. ISSN 0034-6748 (printed). DOI: 10.1063/1.1138545.