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Bipolar Electrochemical Displacement: A New Phenomenon with Implications for Self‐Limiting Materials Patterning
Author(s) -
Braun Trevor M.,
Schwartz Daniel T.
Publication year - 2016
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201500356
Subject(s) - materials science , ohmic contact , nickel , electrochemistry , displacement (psychology) , copper , coupling (piping) , electrode , drop (telecommunication) , etching (microfabrication) , substrate (aquarium) , mechanics , scaling , chemical physics , composite material , metallurgy , chemistry , geometry , physics , mechanical engineering , geology , psychology , oceanography , mathematics , layer (electronics) , engineering , psychotherapist
Bipolar electrochemical displacement (BED) enables direct‐write electrodeposition on a conducting substrate that has no electrical connection. We demonstrate this phenomenon using nickel deposition coupled to the equal and opposite displacement of copper. The driving force for BED is the solution potential gradient generated by a specially configured rastering microjet electrochemical cell. BED is self‐limiting based on the quantity of metal available for displacement from the substrate. Finite‐element method simulations are used to show how the coupling between solution ohmic drop and charge transfer kinetics control bipolar efficiency and spatial segregation of the electrochemistry. Experiments and simulations show that the electrodeposition of nickel is largely dictated by the potential gradients in the microjet region, and largely unaffected by details of copper etching far from the microjet. Simple analytical scaling arguments explain most of the experimental trends.