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Silicon carbide (SiC) has great potential for optomechanical applications due to its outstanding optical and mechanical properties. However, challenges associated with SiC nanofabrication have constrained its adoption in optomechanical devices, as embodied by the considerable optical loss or lack of integrated optical access in existing mechanical resonators. In this work, we overcome such challenges and demonstrate a low-loss, ultracompact optomechanical resonator in an integrated 4H-SiC-on-insulator (4H-SiCOI) photonic platform for the first time, to our knowledge. Based on a suspended 4.3-μm-radius microdisk, the SiC optomechanical resonator features low optical loss (<1 dB/cm), a high mechanical frequencyfmof 0.95×109 Hz, a mechanical quality factorQmof 1.92×104, and a footprint of <1×10−5 mm2. The correspondingfm·Qmproduct is estimated to be 1.82×1013 Hz, which is among the highest reported values of optomechanical cavities tested in ambient environment at room temperature. In addition, the strong optomechanical coupling in the SiC microdisk enables coherent regenerative optomechanical oscillations at a threshold optical dropped power of 14 μW, which also supports efficient harmonic generation at increased power levels. With such competitive performance, we envision a range of chip-scale optomechanical applications to be enabled by the low-loss 4H-SiCOI platform.
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Non-Resonant Vibration Energy Harvester for Sub-Hertz and Sub-G Vibration
This paper presents a non-resonant vibration energy harvester (VEH) optimized for 0.5-1.0 Hz at 0.2g acceleration, typically associated with human motion in daily activities. Different amounts of water-based and oil-based ferrofluids as liquid bearings have been studied in an experimental setup with a precisely controllable spacing between top and bottom coil plates where the magnet array and ferrofluid bearings reside. The sub-miniature VEH (1.4cc and 3.3gram) steadily generates voltages between 0.5-1.0 Hz and is measured to produce an open-circuit voltage of Vrms = 19.5 - 31.9 mV (or 0.33-0.89 μW into a match load) from 0.2g sub-Hz applied acceleration. The highest figure of merit (FOM) of the VEH at 0.2g at 1.0 Hz is 15.5 μW/cc/g2.
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- Award ID(s):
- 1911369
- PAR ID:
- 10512859
- Publisher / Repository:
- IEEE
- Date Published:
- Journal Name:
- Hilton Head Workshop 2024: A Solid-State Sensors, Actuators and Microsystems Workshop
- Subject(s) / Keyword(s):
- Vibrational Energy Harvesters, Wearable Devices, Human Motion, Self-power, Sustainable Energy, Power MEMS, Non-Resonant Electromagnetic Energy Conversion, Ferrofluids
- Format(s):
- Medium: X
- Location:
- Hilton Head Island, SC
- Sponsoring Org:
- National Science Foundation
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