Programmed Logic Operation-Based Controlled Movement of Self-Destructive Microbots for Toxic Pesticide Degradation

Abstract

To foster the locomotion of micro/nanobots in dynamic environmental conditions, it is essential to design a bot that is adaptable and effective in harsh circumstances; hence, this could also be apt for real-life applications. Moreover, it would be advantageous to control the autonomous propulsion of the bot in the form of Boolean logic expression using stimuli such as pH, temperature, viscosity, and fuel concentration. The present microbot made of carbon dots, iron-oxide nanoparticles, and a thermosensitive polymer showed programmable propulsion, either cascading multiple or individual logic gate propulsion, while different combinations (two systems and three systems) of these stimuli were preserved in the medium. As a proof-of-concept, the designed bots were effectively used for the degradation of hazardous pesticides in the aqueous medium, as these pesticides present a huge concern for human health and the environment. Interestingly, the fate of the bots could also be monitored, as they are reusable after magnetic separation or they self-destruct, depending on the temperature of the medium, due to the presence of a thermosensitive polymer. Therefore, it is deemed that low cytotoxicity, economical precursors, and the large distance swimming ability in harsh environments would make these bots viable options for water treatment.