| 研究課題/領域番号 |
21K04151
|
|---|
| 研究機関 | 東京農工大学 |
|---|
研究代表者 |
張 亜 東京農工大学, 工学(系)研究科(研究院), 准教授 (80779637)
|
|---|
| 研究期間 (年度) |
2021-04-01 – 2024-03-31
|
| キーワード | MEMS resonantor / nonlinearity / internal mode coupling / MEMS sensor |
|---|
| 研究実績の概要 |
This research aims at clarifying the nonlinear mode coupling effect in MEMS beam resonator to achieve high sensitivity terahertz sensing. In the research of this year, we have focused on deriving the mode coupling strength, and performing nonlinearity tuning to improve the thermal sensitivity of MEMS resonators.
We have obtained the mode coupling coefficient by measuring the coupling-induced resonance frequency shift. The 1st bending mode of a MEMS resonator was driven in the self-oscillation mode. Simultaneously we drove a higher resonance mode and measured the frequency shift of the 1st bending mode, from which the mode coupling strength between these two modes has been derived. The derived mode coupling strength reasonably agrees with the numerical calculation. The obtained result is useful for clarifying the physical origin of the mode coupling effect.
Furthermore, we have discovered a thermal tuning effect of the mechanical nonlinearity in MEMS resonator. It is known that the mechanical nonlinearity is highly related with the mode coupling effect. MEMS resonator shows hardening nonlinearity with a small linear oscillation amplitude. When an electrical heat is applied to the MEMS beam, we have observed a significant reduction in the mechanical nonlinearity of the MEMS resonators. With the nonlinearity tuning, MEMS resonator can maintain a 10 times enhanced quasi linear oscillation amplitude, which is promising for low noise operation of MEMS resonators.
|
| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
The research is progressing rather smoothly. We have achieved the measurement of the mode coupling strength, as well as a theoretical understanding and experimental tuning of the mechanical nonlinearity of MEMS beam resonators. These achievements form a solid basis for clarifying the physical origin of the mode coupling effect.
Moreover, during the study of mode coupling effect, we have developed a new technique for measuring the resonance mode shape of MEMS resonator with a simple DIC microscope. This technique will allow us to directly imaging the internal mode resonance, and play a key role in next-step research.
|
| 今後の研究の推進方策 |
The plan for the future work is shown as follows.
1. We will perform both theoretical and experimental research to clarify the physical origin of the mode coupling effect in MEMS resonators. In particular, the DIC microscope will be used to directly observe the internal mode resonance of the coupled modes. So that, the relation between the resonance condition and the enhancement in the thermal responsivity can be preciously determined.
2. Utilizing the knowledge obtained above, we will optimize the structure of MEMS beams to achieve a high thermal responsivity for terahertz sensing applications.
|
| 次年度使用額が生じた理由 |
Affected by the COVID-19, the international and domestic conferences all became online attendances. Therefore, the planed travel expense has not been used for this year.
The incurring amount will be used for purchasing consumers(high purity chemicals, low price optical components, and etc) for the sample fabrications and measurements in the future.
|
