3D hemispherical microstructure, fabricated with femtosecond laser-based two-photon polymerization technique which encapsulates 1 μm polystyrene probe particle. The VideoInside(S1) shows the trapping and micromanipulation of the probe particle using optical tweezers inside the fabricated structure. At the boundary of the hemisphere, the particle leaves the optical trap as it cannot be moved out of the structure, indicating that the walls are mechanically stable and do not exhibit holes larger than 1 μm.