Swimming Microrobots: Soft, Reconfigurable, and Smart

Using materials with properties similar to those of cells and microorganisms together with innovative fabrication methods, soft and smart microrobots can be developed, with increased adaptability and flexibility toward in vivo applications. These tiny robots are designed to carry out difficult tasks such as noninvasive microsurgery, diagnosis and therapy in complex environments, including viscous media and intricate channels. Moreover, the novel property of the soft materials to respond to stimuli has paved the way for the creation of reconfigurable and smart microrobots with both actuation and function (e.g., sensing, drug delivery) capabilities. This feature article aims to give an overview of the different soft and smart swimming microrobots (less than 1 mm in all dimensions), highlighting some aspects of new materials, their development and the challenges in their processing to obtain highly functional microrobots. In this feature article, the latest developments of soft microrobots are presented. Novel materials and fabrication techniques are thoughtfully described, providing an overview of the current possibilities to build soft and smart swimming microrobots with advanced features such as reconfigurable morphologies, advanced control mechanisms, and multifunction capabilities.