Light-driven micro/nanobots

Modern technological evolution witnesses a fast-paced progress in the design, science, and technology of light-driven micro/nanomachines in the recent past. These micromachines have found enormous applications as micro/nanoscale manipulators, micromachined space exploration components, nano-sized cell positioning and control, and micro/nanorobots for drug delivery to name a few. This is not only due to their smaller size but also due to an ever-demanding necessity of micro/nanoscale functionalities with touch-free optimum control incorporating features such as propulsion, self-powered and controlled activation, energy efficiency, intelligence, navigation, and tracking. It also motivates one for biomimicking the functionalities of several living organisms to mold the ideas into micro/nanorobots to understand their properties and the underlying physics. Incorporating the magical functionalities enabled by nano/micro photonics answer many a challenge while they also open a wide range of possibilities ahead. Here, we present light-driven micro/nanorobots (µn-Bots) whose robotic features and functionalities are envisaged to have potential applications in medicine, industry, rescue, and strategic deterrence, pertaining to all walks of life and spectrums. After giving a comparative as well as the state of art outline on advances on the diverse technological innovations of µn-Bots in general, we comprehensively go through the light-driven micro/nanorobot designs and explore their functionalities, materials, and micro/nanofabrication techniques concerning their recent advances and multifaceted applications. On the other hand, we also give an analysis on the performance matrix of the reported light-driven micro/nanorobots explicitly studied in the recent past and give an outlook on the future roadmap and trends.