The University of Southampton
University of Southampton Institutional Repository

In-situ contact surface characterization in a MEMS ohmic switch under low current switching

In-situ contact surface characterization in a MEMS ohmic switch under low current switching
In-situ contact surface characterization in a MEMS ohmic switch under low current switching
To develop robust microelectromechanical systems (MEMS) switching technology for low voltage direct current (DC) applications (1–12 V) there is a requirement for the investigation of wear caused by hot switching (contact operated while carrying a current load). Previous investigation of contact wear in the ohmic MEMS switch has been limited to either the completion of the contact switching cycles, where the device is destructively opened, or by low switching rates, making lifetime testing impractical. A novel MEMS testing platform is described that is capable of both resolving microscale changes on the contact surface between switching events and sustained high frequency switch cycling, enabling practical lifetime testing. The platform is used to investigate early surface changes in a thin-film Au contact pair on a cycle-by-cycle basis. The contact is closed at forces representative of a practical MEMS contact (<1 mN). The apparatus reveals the microscopic surface change between individual switching events. Hot switched contact wear is dominated by the molten metal bridge (MMB) phenomenon, linked to a characteristic voltage transient at contact opening and the gradual process of contact material transfer; however, during hot switching delamination phenomena are also observed, and associated with a step change in contact voltage and a greater level of surface damage.
2227-7080
Bull, Thomas G.
93bf0964-0be6-44a8-a4e3-f1637c509728
McBride, John W.
d9429c29-9361-4747-9ba3-376297cb8770
Bull, Thomas G.
93bf0964-0be6-44a8-a4e3-f1637c509728
McBride, John W.
d9429c29-9361-4747-9ba3-376297cb8770

Bull, Thomas G. and McBride, John W. (2018) In-situ contact surface characterization in a MEMS ohmic switch under low current switching. Technologies, 6 (2), [47]. (doi:10.3390/technologies6020047).

Record type: Article

Abstract

To develop robust microelectromechanical systems (MEMS) switching technology for low voltage direct current (DC) applications (1–12 V) there is a requirement for the investigation of wear caused by hot switching (contact operated while carrying a current load). Previous investigation of contact wear in the ohmic MEMS switch has been limited to either the completion of the contact switching cycles, where the device is destructively opened, or by low switching rates, making lifetime testing impractical. A novel MEMS testing platform is described that is capable of both resolving microscale changes on the contact surface between switching events and sustained high frequency switch cycling, enabling practical lifetime testing. The platform is used to investigate early surface changes in a thin-film Au contact pair on a cycle-by-cycle basis. The contact is closed at forces representative of a practical MEMS contact (<1 mN). The apparatus reveals the microscopic surface change between individual switching events. Hot switched contact wear is dominated by the molten metal bridge (MMB) phenomenon, linked to a characteristic voltage transient at contact opening and the gradual process of contact material transfer; however, during hot switching delamination phenomena are also observed, and associated with a step change in contact voltage and a greater level of surface damage.

Text
MPDI Final Submitted 3-5-18 Post Inspection - Accepted Manuscript
Available under License Creative Commons Attribution.
Download (20MB)
Text
technologies-06-00047 - Version of Record
Available under License Creative Commons Attribution.
Download (7MB)

More information

Accepted/In Press date: 1 May 2018
e-pub ahead of print date: 4 May 2018

Identifiers

Local EPrints ID: 420441
URI: http://eprints.soton.ac.uk/id/eprint/420441
ISSN: 2227-7080
PURE UUID: 806e6e10-1a6c-4d2d-989a-bcaf0480253c
ORCID for John W. McBride: ORCID iD orcid.org/0000-0002-3024-0326

Catalogue record

Date deposited: 08 May 2018 16:30
Last modified: 16 Mar 2024 02:37

Export record

Altmetrics

Contributors

Author: Thomas G. Bull
Author: John W. McBride ORCID iD

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×