Soft creeping robots have great potential in fields of search-and-rescue for their excellent body compliance and adaptability in unstructured environments and the capacity of passing through a narrow space. But most of the reported soft creeping robots can only crawl forward or backward except a few ones can swerve using a differential actuation mechanism, the maneuverability of the existing soft creeping robots are generally poor which limits their practical applications. In this paper, we design a soft creeping robot driven by dielectric elastomer (DE) which has the ability of omnidirectional movement. The robot mainly consists of a circular deformable body and six thin feet which are evenly distributed around the body circumference. The robot body is an annular dielectric elastomer actuator (ADEA) made by connecting a six-segment dielectric elastomer minimum energy structure end to end, which has excellent ability of active deformation controlled by applied voltages. The six feet are essentially six paper-based electroadhesion actuators which can achieve adhesion or detachment with the ground. Experimental tests for the active deformation performance of the ADEA are implemented for optimizing design of the robot. Then through activating different DE segments, the ADEA deforms from a circle to an ellipse or some irregular shapes, cooperating actuation with the six electroadhesion actuators the robot realizes free movement towards twelve directions around the plane.
As a unique type of driving force, the transverse optical gradient force has been extensively studied and applied in the nanowaveguides resonator. Recently, it is demonstrated that the optical forces in slot waveguides of hyperbolic metamaterials can be over two orders of magnitude stronger than that in conventional dielectric slot waveguides. To investigate the nonlinear dynamic characteristic of hyperbolic waveguide resonator driven by optical gradient force, a continuum elastic model of the optoresonator is presented and analytically solved using the methods of Rayleigh–Ritz and multiple scales. The results show that the optical force is strengthened with the increase of the filling ratio of silver in the hyperbolic waveguide. The resonance frequency becomes greater with the increase of the filling ratio of silver no matter what the geometric parameters and physical property parameters are. However, the steady maximum vibration amplitude becomes smaller, and the degree of system stiffness softening also reduces.
Solar light pipe combined with Photocatalysis to depredate formaldehyde under cloudy conditions in summer were
tested in Beijing. The solar light pipe used in the experiment is a straight solar light pipe, which is 550mm long, with
diameters of 280mmmm Degussa P25 titanium dioxide ("Degussa", Germany) as photocatalyst was coated on the surface
of the emitter of the solar light pipe. The test chamber made up of stainless steel is 0.1m3. The experiment results
showed obvious effect on decomposing formaldehyde of solar light pipe combined with Photocatalytic under cloudy
conditions. The volume fraction of formaldehyde reduced from 1.0x10-6 to 0.16x10-6 during 35min and the value
reduced from 1.0x10-6 to 0.10x10-6 during 60min under cloudy conditions. The experiment showed that Photocatalytic
by the radiations of sunlight under sunny conditions also has good effect for air cleaning.