Phase transition induced micromechanical actuation in VO2 coated cantilever

Rajeswaran, Bharathi and Viannie, L R and Rajanna, K and Jayanth, G R and Umarji, A M (2018) Phase transition induced micromechanical actuation in VO2 coated cantilever. In: JOURNAL OF APPLIED PHYSICS, 124 (7).

PDF Jou_App_Phy_124-7_074502_2018.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

Structural phase transition assisted micromechanical actuation of a vanadium dioxide (VO2) coated silicon microcantilever is presented. A 300 nm polycrystalline VO2 film was deposited over the silicon surface at 520 degrees C using metal organic chemical vapor deposition. The formation of the M1 monoclinic phase of the as-deposited VO2 film was confirmed by X-ray diffraction studies and further verified by temperature variable Raman spectroscopy. The heated VO2 film exhibits semiconductor-to-metal transition at 74 degrees C, which produces a change in the electrical resistance almost of three orders in magnitude. Consequently, the VO2 film undergoes structural phase transition from the monoclinic phase (011)(M1) to a tetragonal phase (110)(R). This generates a compressive stress within the VO2 film resulting in large, reversible cantilever deflection. This deflection was measured with a non-contact 3D optical profilometer, which does not require any vacuum conditions. Upon heating, the VO2 coated silicon cantilever produced a large reversible tip deflection of 14 mu m at 50 degrees C. Several heating and cooling cycles indicate steep changes in the cantilever tip deflection with negligible hysteresis. In addition, the effect of thermal stress induced cantilever deflection was estimated to be as small as 6.4%, and hence can be ignored. These results were found to be repeatable within controlled experimental conditions. Published by AIP Publishing.

Item Type:	Journal Article
Publication:	JOURNAL OF APPLIED PHYSICS
Publisher:	AMER INST PHYSICS
Additional Information:	Copy right for this article belong to AMER INST PHYSICS, 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA
Department/Centre:	Division of Chemical Sciences > Materials Research Centre Division of Physical & Mathematical Sciences > Instrumentation Appiled Physics
Date Deposited:	24 Sep 2018 15:37
Last Modified:	24 Sep 2018 15:37
URI:	http://eprints.iisc.ac.in/id/eprint/60698

Actions (login required)

View Item