Nanoradiator-Mediated Deterministic Opto-Thermoelectric Manipulation

Yaoran Liu, Linhan Lin, Bharath Bangalore Rajeeva, Jeremy W. Jarrett, Xintong Li, Xiaolei Peng, Pavana Kollipara, Kan Yao, Deji Akinwande, Andrew K. Dunn, and Yuebing Zheng

Optical manipulation of colloidal nanoparticles and molecules is significant in numerous fields. Opto-thermoelectric nanotweezers exploiting multiple coupling among light, heat, and electric fields enables the low-power optical trapping of nanoparticles on a plasmonic substrate. However, the management of light-to-heat conversion for the versatile and precise manipulation of nanoparticles is still elusive. Herein, we explore the opto-thermoelectric trapping at plasmonic antennas that serve as optothermal nanoradiators to achieve the low-power (∼0.08 mW/μm2) and deterministic manipulation of nanoparticles. Specifically, precise optical manipulation of nanoparticles is achieved via optical control of the subwavelength thermal hot spots. We employ a femtosecond laser beam to further improve the heat localization and the precise trapping of single ∼30 nm semiconductor quantum dots at the antennas where the plasmon–exciton coupling can be tuned. With its low-power, precise, and versatile particle control, the opto-thermoelectric manipulation can have applications in photonics, life sciences, and colloidal sciences.

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