In this paper, we studied the problem of multi-robot target searching. We contributed to the current state-of-the-art by proposing a novel mechanism to increase the convergence speed based on a repulsion mechanism between similar ions. In this article, we perceive robots as ions, wherein the main purpose of the adopted approach is to keep the level of diversity among the robots stable. This mechanism will be applied to a particle swarm optimization (PSO) approach, denoted as Robotic Darwinian PSO (RDPSO). This improvement was done to speed up the previously proposed approaches and to provide accurate search results. The results depict the superiority of the proposed approach both in terms of speed and search result. Also, the proposed approach shows a superior performance when it is compared with other approaches as the number of robots decreases.