171 / 2024-06-14 14:55:33

Research on super-resolution imaging using liquid-immersed randomly generated polymer droplet microspheres

super-resolution imaging,polymer droplet microspheres,liquid immersion,resolution criterion,numerical simulation

Among the numerous nano-imaging techniques, microsphere-assisted super-resolution imaging technology has garnered widespread attention and rapid development over the past decade due to its features and advantages such as label-free operation, high resolution, cost-effectiveness, real-time observation, and ease of integration [1-3]. Introducing immersion liquid in microsphere-assisted super-resolution imaging not only effectively enhances imaging performance, including contrast, resolution, magnification, and clarity, but also greatly facilitates the adaptation of microsphere-assisted microscopy for applications in biological imaging scenarios.

In this work, a simple and convenient self-assembly method, for the generation of polymer droplet microspheres immersed in liquid with random sizes and positions, was proposed and demonstrated. The polymer droplet microspheres at random positions, as shown in Fig. 1(a), primarily have a size distribution in the range of approximately 3-10 μm, with the highest quantity of microspheres having a diameter of around 5 μm. Here, the material used for the polymer droplet microspheres is the optical adhesive previously used to fabricate spherical cap optical nanoscopy [4]. The immersion liquid is polydimethylsiloxane elastomer.

We researched super-resolution imaging by combining these liquid-immersed polymer droplet microspheres with conventional optical microscopy. The schematic diagram is shown in Fig. 1(b). The resulting image is a magnified virtual image with the image plane located below the sample. Figure 1(c) shows the imaging result of the gratings on a Blu-ray disc with a minimum feature size of 100 nm, obtained using the microsphere lens-assisted microscope. The inset in the upper right corner is the SEM image of the grating stripes on the Blu-ray disc. The possible mechanisms by which liquid-immersed polymer droplet microspheres achieve super-resolution imaging were investigated based on resolution criterion judgments and numerical simulations using the finite element method. The research presented here holds promise as a potential candidate for assisting super-resolution imaging using liquid-immersed polymer droplet microspheres.