pH-Responsive Round-Way Motions of a Smart Device through Integrating Two Types of Chemical Actuators in One Smart System

Smart motions of objects from the submicrometer to millimeter scale through chemical control with stimulus-responsive way are significant to achieve various applications. However, the intelligence of the current devices with chemical responding system remains to be improved; especially, achieving a round-way motion is still a challenge. Therefore, two types of actuators are simultaneously integrated into single smart device at the opposite ends to achieve cooperated functions in an orderly manner. 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.