Graphene-Based Opto-Thermoelectric Tweezers.

Since the discovery of graphene, its excellent physical properties have greatly improved the performance of optoelectronic devices and brought important technological advances to optical research and its applications. Here, graphene is introduced to the field of optical-tweezer technology and demonstrate a new graphene-based opto-thermoelectric tweezer. This technology not only reduces the incident light energy required by two orders of magnitude (compared with traditional optical tweezers), it also brings new advantages such as a much broader working bandwidth and a larger working area compared to those of widely researched gold-film-based opto-thermoelectric tweezers. Compared with gold film, graphene exhibits higher thermal conductivity and higher uniformity and is easier to process. Thus, it is found that even monolayer graphene provides stable trapping for particles in a broad bandwidth and that performance is enhanced as the number of graphene layers increases. Furthermore, parallel trap multiple particles as desired shapes can be easily generated with structured graphene patterns. This work demonstrates the enormous application potential of graphene in optical-tweezer technology and will promote their application to the trapping or concentration of cells and biomolecules as well as to microfluidics and biosensors.