The field of self-propelled nano-and microparticles, known collectively as nanomotors, celebrated its 20 th birthday following two decades of continuous growth. Its inception can be traced to an experimental paper from the Pennsylvania State University in 2004 , followed closely by another publication from the University of Toronto 2 . Around the same time, two conference papers from the Swiss Federal Institute of Technology in Zürich described magnetic nanomotors . Independently, a theoretical paper suggested the possibility of the design of nanomotors based on the asymmetric distribution of reaction products , Fig. . The first experimental nanomotors were bimetallic rods propelled by the catalytic conversion of hydrogen peroxide to products produced asymmetrically across the body of the nanomotors, leading to force-free phoretic transport . Another class of chemical nanomotors achieved propulsion by the generation of gas bubbles inside micro-tubular jets, which were expelled preferentially from one end, enabling directional motion .