PH-Rsponsive Round-Way Motions Of A Smart Device Through Intergrating Two Types Of Chemical Actuaors In One Smart System

Stimulus responsive intelligent materials,which is the fourth generation of materials after the natural materials, synthetic polymer materials and artificial materials, will be one of the important direction of development of new materials and support the development of technology in the future. However, the traditional stimulus-responsive materials already can't meet human needs because they only have one single kind of responsiveness and functionality. Therefore, intelligent materials with multiple responsiveness and functionality has the vast development potential and broad prospects in application.How can we improve the application of intelligent materials? It's need to improve the multiple stimulus-responsive of smart devices and solve some open problems. Motions of small objects from the submicro to millimeter scale have gained increasing attention for potential applications in microscale robotics and motors, manipulation of cell or bacteria, drug delivery, directed transportation, sensing, electricity generation, macroscopic assembly, etc. However, there remains the challenge of promoting the motions of small objects from an autonomous manner to controlled locomotion that responds to a stimulus, particularly responsive on/off motions; We reported the continuous on-off-on locomotion of a smart device by integrating pH-responsive smart materials as the switch and platinum-catalyzed bubble propulsion as the power resource in a single system. However, one actuator could only propel the device in one-way single direction, and it was difficult to alter the locomotion direction in position with the same actuator. Therefore, two actuators attached to two opposite ends of the device, the smart device could realize round-way motions adjusted through sequential triggering of the above two actuators. One actuator is the pH-responsive power supply of hydrogen bubbles produced from the reaction between magnesium and HCl. The smart device undergoes on-off-on locomotion through control over the solution pH values by using the pH responsive actuator of magnesium-HCl system. The other actuator is the hydrogen peroxide-responsive system of oxygen bubbles generated through the decomposition of hydrogen peroxide catalyzed by platinum aggregates. When introducing hydrogen peroxide solution into the system, the generated oxygen bubbles at the opposite end of the device to push the device backward for round-way motions. For the first time, two different types of actuators are simultaneously integrated into single smart device without disturbing each other, which realize pH-responsive round-way motions of the smart device and improve the system intelligence for further applications.