scholarly journals A Benchmark Study for Phase Transformation of Shape Memory Alloy Based Split Ring Resonator Structure Under a Heating and Cooling Thermal Cycle

2020 ◽  
Vol 11 (1) ◽  
pp. 239-250
Author(s):  
Mehmet Mete ÖZTÜRK ◽  
Bahadır DOĞAN
Keyword(s):  
Phase Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Thermal Cycle ◽  
Ring Resonator ◽  
Split Ring Resonator ◽  
Split Ring ◽  
Benchmark Study ◽  
Resonator Structure ◽  
Heating And Cooling

Maximum Attainable Deflections of Shape Memory Alloy-Layered Microcantilever

2008 ◽  
Vol 5 (2) ◽  
pp. 52-61
Author(s):  
P. Majumder ◽  
A. Bhattacharyya
Keyword(s):  
Phase Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Case Analysis ◽  
Nickel Titanium ◽  
Surveillance Systems ◽  
Computational Results ◽  
Heating And Cooling ◽  
Out Of Plane ◽  
Cantilever Surface

Finite element modeling of a shape memory alloy (SMA)-layered microcantilever is reported herein. It is assumed that the SMA layer is “two-way–trained,” such that alternate heating and cooling of the SMA layer will cause a phase transformation in the SMA layer and deform the cantilever out-of-plane and back. For a nickel–titanium (NiTi) layer on a glass substrate, computational results indicate that a uniform 4% two-way strain along the length of a SMA layer spanning the full length of a 100-μm cantilever translates to a tip deflection of 29.5 μm, and a sweep of approximately 30° from the flat “rest” state. As well, 40% of the cantilever surface (measured from its free end) is flat and can be used as a flat reflective surface for micromirror applications. A “worse-case” analysis is presented where only 50% of the SMA length is able to undergo phase transformation, resulting in deflections of about 10 μm with a 12° sweep. Finally, it is shown that deflections are about two orders of magnitude higher than what would be possible if the SMA layer did not undergo phase transformations (but underwent pure thermal expansion only). One possible area of application could be in the area of continuously rotating micromirrors, suitable for surveillance systems.

Compact Tri-Band Microstrip Patch Antenna Using Complementary Split Ring Resonator Structure

2021 ◽  
Vol 36 (3) ◽  
pp. 346-353
Author(s):  
Narayanasamy Rajesh Kumar ◽  
Palan Sathya ◽  
Sharul Rahim ◽  
Muhammed Nor ◽  
Akram Alomainy ◽  
...  
Keyword(s):  
Ring Resonator ◽  
Split Ring Resonator ◽  
Microstrip Patch Antenna ◽  
Split Ring ◽  
Suitable Candidate ◽  
Complementary Split Ring Resonator ◽  
Microstrip Patch ◽  
Resonator Structure ◽  
Metamaterial Antenna ◽  
Good Comparison

In this letter, a compact complementary split ring based tri-band antenna is proposed. The proposed antenna resonates at 1.9 GHz (1.70-1.91 GHz), 2.45 GHz (2.23-2.52 GHz) and 3.2 GHz (2.9-3.25 GHz); the input match values are 24.56 dB, 27.21 dB and 22.46 dB, respectively. The antenna’s realised peak gain is 4.15 dBm at 1.9 GHz, 4.25 dBm at 2.4 GHz and 4.74 dBm at 3.2 GHz, with approximately 42% of reduction in antenna size. The results demonstrate that the proposed metamaterial antenna is tunable, electrically small and highly efficient, which makes it a suitable candidate for RF energy harvesting. The antenna is numerically and experimentally analysed and validated with very good comparison between the simulated and measured results.

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