Zhang Chenchen, Cocking Alexander, Freeman Eugene, Liu Zhiwen, Tadigadapa Srinivas
School of Electrical Engineering and Computer Science, Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA.
Sci Rep. 2017 Nov 2;7(1):14965. doi: 10.1038/s41598-017-14049-w.
Arrays of on-chip spherical glass shells of hundreds of micrometers in diameter with ultra-smooth surfaces and sub-micrometer wall thicknesses have been fabricated and have been shown to sustain optical resonance modes with high Q-factors of greater than 50 million. The resonators exhibit temperature sensitivity of -1.8 GHz K and can be configured as ultra-high sensitivity thermal sensors for a broad range of applications. By virtue of the geometry's strong light-matter interaction, the inner surface provides an excellent on-chip sensing platform that truly opens up the possibility for reproducible, chip scale, ultra-high sensitivity microfluidic sensor arrays. As a proof of concept we demonstrate the sensitivity of the resonance frequency as water is filled inside the microspherical shell and is allowed to evaporate. By COMSOL modeling, the dependence of this interaction on glass shell thickness is elucidated and the experimentally measured sensitivities for two different shell thicknesses are explained.
已经制造出直径为数百微米、表面超光滑且壁厚为亚微米级的片上球形玻璃壳阵列，并且已证明其能够维持品质因数大于5000万的光学共振模式。这些谐振器的温度灵敏度为-1.8 GHz/K，可配置为适用于广泛应用的超高灵敏度热传感器。由于该几何结构具有强烈的光与物质相互作用，其内表面提供了一个出色的片上传感平台，真正开启了可重现的、芯片规模的、超高灵敏度微流体传感器阵列的可能性。作为概念验证，我们展示了在微球壳内填充水并使其蒸发时共振频率的灵敏度。通过COMSOL建模，阐明了这种相互作用对玻璃壳厚度的依赖性，并解释了两种不同壳厚度的实验测量灵敏度。
