Robotic Actuator Mimicking Serpentine Locomotion

At present, the structures that people have built to mimic serpentine locomotion mostly use motor as power output. Our objective in this project is to find a new method to drive a newly designed serpentine locomotion mimicking structure. We will focus on utilizing electromagnetic (EM) interaction as the means of powering in our research as EM is considered having higher energy density. The robotic actuator that mimics serpentine locomotion will have multiple sections as links within the structure. Each section in the “snake” shaped robotic actuator will produce some torque. Through a collective effort, the whole structure will move like a snake. The design objective is that, when compared with a traditional motor-driven actuator, our design has a higher power density.Ope

Photonic Metamaterials: Controlling Nanoscale Radiative Thermal Transport

We discuss concepts of radiative thermal diodes demonstrating dynamic control and modulation of radiative heat transfer. These concepts are analogous to electronic diodes and display high degree of asymmetry in radiative heat transfer. Change in optical properties of vanadium dioxide VO 2 upon phase transition are exploited to influence thermal radiation. The first concept is based on a simple multi-layer structure containing a layer of VO 2 to attain dynamic optical response in the far-field regime. The active terminal of the diode changes from highly reflecting to highly absorbing upon phase transition of VO 2 . In the second concept, a near-field thermal diode is considered that utilizes period gratings of VO 2 . Radiative heat transfer across the near-field gap is modulated by altering tunneling of surface waves when phase change in VO 2 occurs. For minimal temperature difference of 20 K, rectification ratios have been reported and they are maximum in existing literature for comparable operating temperatures and configurations

Mechanical Deformation Induced Continuously Variable Emission for Radiative Cooling

Passive radiative cooling drawing the heat energy of objects to the cold outer space through the atmospheric transparent window (8 um - 13 um) is significant for reducing the energy consumption of buildings. Daytime and nighttime radiative cooling have been extensively investigated in the past. However, radiative cooling which can continuously regulate its cooling temperature, like a valve, according to human need is rarely reported. In this study, we present a concept of reconfigurable photonic structure for the adaptive radiative cooling by continuously varying the emission spectra in the atmospheric window region. This is realized by the deformation of the one-dimensional PDMS grating and the nanoparticles embedded PDMS thin film when subjected to mechanical strain. The proposed structure reaches different stagnation temperatures under certain strains. A dynamic exchange between two different strains results in the fluctuation of the photonic structure's temperature around a set temperature