A molecular robot is a microorganism-imitating micro robot that is designed from the molecular level and constructed by bottom-up approaches. As with conventional robots, molecular robots consist of three essential robotics elements: control of intelligent systems, sensors, and actuators, all integrated into a single micro compartment. Due to recent developments in microfluidic technologies, DNA nanotechnologies, synthetic biology, and molecular engineering, these individual parts have been developed, with the final picture beginning to come together. In this review, we describe recent developments of these sensors, actuators, and intelligence systems that can be applied to liposome-based molecular robots. First, we explain liposome generation for the compartments of molecular robots. Next, we discuss the emergence of robotics functions by using and functionalizing liposomal membranes. Then, we discuss actuators and intelligence via the encapsulation of chemicals into liposomes. Finally, the future vision and the challenges of molecular robots are described.

This paper reports the first demonstration of a self-powered environmental monitoring robot which backpacked a biofuel cell (BFC) and a micro wireless sensor module on insect. Electric power was generated from blood sugar in its hemolymph by using the BFC and temperature and humidity around it was monitored by using the wireless sensor module. Furthermore, the robot moves autonomously by the intention of insect. First, the BFC which can be backpacked cockroaches was fabricated with a 3D printer. The electrochemical reaction of the anode in the insect-mountable BFC (imBFC) was evaluated and an oxidation current of 1.18 mA/cm² (at +0.6 V vs. Ag|AgCl) was observed. Then, the performance of the imBFC was evaluated and a maximum power output of 333 μW (at 0.5 V) was obtained. Furthermore, a wireless temperature and humidity sensor was successfully driven by the imBFC. Finally, the imBFC and the micro wireless sensor module were mounted on the insect and environmental monitoring was done by the insect. These results indicate that the insect which backpacked the self-powered battery and micro wireless sensors has sufficient potential as microrobots for environmental monitoring and searching in disasters.