Scanning Liquid-Immersed Microsphere Optical Superresolution Imaging Based on Microrobotics Manipulation

Images with resolution beyond the diffraction limit (superresolution) were obtained by combining conventional microscopy with microscale microsphere, which provides a new possibility for real-time optical superresolution imaging. Here, we propose a method to manipulate the microsphere by attaching it to a probe with optical glue. The optical simulation has been performed to demonstrate the influence of probe on superresolution image. The probe was fixed on a translation stage which was regarded as a robotic manipulator with four degrees of freedom. The kinematic analysis of the robotic manipulator was studied for manipulation strategy of microsphere. The force analysis has been carried out to analyze the possibility of microsphere detach from probe. To improve imaging quality, the microsphere was immersed in liquid medium and the resolution of 130 nm (~λ/4.5) was achieved. In addition, by scanning the microsphere at the speed of 5 μm/s over the sample surface and stitching the recorded images, the superresolution image of large continuous area was achieved. This work had important practical significance for manipulating microsphere and optical superresolution imaging.