Opto-Thermo-Mechanical Microsystems for Energy Conversion and High Precision Sensing

我的计划的总体理念是利用基础纳米科学的最新进展，并将它们转化为新的颠覆性应用技术。遵循这一理念，我们对这项提议的具体目标是利用(1)纳米尺度热传输和(2)光学机械领域的最新进展来创建一类新型的光热机械微系统。这些微系统的潜在应用分为三个子目标：(1)热到电的直接转换，(2)高精度红外和THz光探测，以及(3)高精度振动传感。*我们的第一个目标是利用近场热光光伏(NFTPV)效应创造新型便携式热能发电解决方案。其原理是制造模块，在模块中，来自热源的能量被辐射到一个特别定制的光伏电池，放置在其极端接近的位置，通常为&lt；100 nm，以提高性能。我们将开发高温微机械系统，实现这种100 nm以下的距离控制，并将其与光伏电池集成。我们的目标是实现这项技术的首次演示，从长远来看，这项技术承诺比现有的热电发电机具有更高的转换效率。*我们的第二个目标是利用光机谐振器提高红外(IR)和太赫兹(THz)光电探测器的探测极限。我们将不依赖于传统的(电阻)温度传感器，而是创造出将吸收的辐射与超低损耗微机械谐振器的共振频率相关联的光电探测器。这种方法将消除电气噪声源，使我们能够达到测辐射热计的基本检测极限，比目前的性能提高两个数量级。如果成功，我们的工作将有助于激发红外和太赫兹科学在传感、安全和医疗诊断方面的潜在应用，这些应用往往受到糟糕的探测器性能的限制。*我们的第三个目标是提高振动传感器的灵敏度。机械系统对外界振动的响应由其固有共振频率下的品质因数(最高可达数百万)来增强。然而，这种增强永远不会用于加速度计，因为它只允许在复杂的宽带激励频谱中以一个固定频率进行检测。我们将使用我们最近演示的频率可调的高品质因数谐振器来打破这一限制。将共振增强应用到较宽的频谱将使我们能够达到加速度计的基本噪声极限，这比目前的性能提高了两个数量级。这一改进可能在现有应用中被证明是有用的(例如，早期机器故障监测)，或者启用新的应用(例如，水下航行器的声学跟踪)。

The general philosophy of my program is to harness recent progress from fundamental nanoscale science and translate them to new disruptive applied technologies. Following this philosophy, our specific goal for this proposal is to exploit recent progress from the fields of (1) nanoscale thermal transport and (2) optomechanics to create a novel class of opto-thermo-mechanical microsystems. The potential applications of these microsystems are divided in three sub-objectives: (1) direct conversion of heat to electricity, (2) high precision infrared and THz light detection, and (3) high precision vibration sensing. ******Our first objective is to create novel portable solutions for electricity generation from heat using the Near-Field Thermophotovoltaic (NFTPV) effect. The principle is to build modules in which energy from a heat source is radiated towards a specially tailored photovoltaic cell placed in its extreme proximity, typically <100 nm, for performance enhancement. We will develop high temperature micro-mechanical systems that will allow such sub-100 nm distance control and integrate them with photovoltaic cells. We aim to achieve the first demonstration of this technology which, at term, promises greater conversion efficiencies than existing thermoelectric generators. ******Our second objective is to enhance the detection limit of infrared (IR) and terahertz (THz) photodetectors using optomechanical resonators. Rather than relying on conventional (resistive) temperature sensors, we will create photodetectors that correlate absorbed radiation to the resonance frequency of an ultra-low loss micro-mechanical resonator. This method will eliminate electrical noise sources, which will allow us to reach the bolometer fundamental detection limita two orders of magnitude improvement over current performances. If successful, our work will help bring to life the potential applications of IR and THz science in sensing, security, and medical diagnosis, which are often limited by poor detector performances. ******Our third objective is to enhance the sensitivity of vibration sensors. The response of a mechanical system to external vibration is enhanced by its quality factor (up to several millions) at its natural resonance frequency. This enhancement is however never harnessed in accelerometers as it would allow sensing only at one fixed frequency out of a complex broad-band excitation spectrum. We will break this limitation using our recent demonstration of frequency-tunable high quality factor resonators. Applying resonant enhancement to a broad frequency spectrum will allow us to reach the fundamental accelerometer noise limit, a two orders of magnitude improvement over current performances. This improvement could prove useful in existing applications (e.g., early machine failure monitoring), or enable new ones (e.g. acoustic tracking of underwater vehicles).