Schematic of two systems, i.e., a monomer system consisting of monodisperse particles (blue) and self-propelled particles (SPPs) and a dimer system including rod-like particles and SPPs (red). The rod-like particle is composed of two monodisperse spheres connected by a stiff harmonic spring. The arrow indicates the orientation of the SPP which rotates under the thermal fluctuation. The eye-guiding dot line is drawn to separate the two systems.