Volume 9, Issue 7 2401640
Research Article

Gold Flake-Enabled Miniature Capacitive Picobalances

Jiajie Zhu

Jiajie Zhu

State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027 China

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Yuanbiao Tong

Yuanbiao Tong

State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027 China

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Zhenxin Wang

Zhenxin Wang

State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027 China

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Zhiyong Li

Zhiyong Li

State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027 China

Intelligent Optics & Photonics Research Center, Jiaxing Research Institute, Zhejiang University, Jiaxing, 314000 China

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Lei Zhang

Corresponding Author

Lei Zhang

State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027 China

E-mail: [email protected]; [email protected]

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Xin Guo

Xin Guo

State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027 China

Intelligent Optics & Photonics Research Center, Jiaxing Research Institute, Zhejiang University, Jiaxing, 314000 China

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Limin Tong

Limin Tong

State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027 China

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Pan Wang

Corresponding Author

Pan Wang

State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027 China

Intelligent Optics & Photonics Research Center, Jiaxing Research Institute, Zhejiang University, Jiaxing, 314000 China

E-mail: [email protected]; [email protected]

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First published: 10 December 2024
Citations: 1

Abstract

Measurement of masses of microscale objects or weak force with ultrahigh sensitivity (down to nanogram/piconewton level) and compact configuration is highly desired for fundamental research and applications in various disciplines. Here, by using freestanding gold flakes with high reflectivity (≈98% at 980 nm) as the sample tray and silica microfibers with extremely low spring constant (≈0.05 mN m−1) as the cantilever beams, miniature capacitive balances are reported with piconewton-level detection limit (picobalances) and reliable radiation force-based calibration. In the design, the gold flake is suspended by two silica microfibers, which also functions as an electrode to form a capacitor with an underneath gold electrode. Benefitting from the high reflectivity of the gold flake, the performance of picobalances can be precisely calibrated by exerting piconewton-level radiation pressure on the gold flake (working as a mirror) with a laser, showing a detection limit as low as 6.9 pN. Finally, using a fiber taper-assisted micromanipulation technique, masses of various types of pollens (with weights ranging from 4.6 to 96.3 ng) are readily measured by a picobalance at single-particle level. The miniature picobalances should find applications in precise measurement of masses of micro or nanoscale objects and various types of weak forces.

Conflict of Interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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