How Artificial “Nano Sunflowers” Can Help Harvest Solar Energy?22/11/2019
Many living organisms track light sources and change their behavior to benefit from it. We call it “phototropism,” and the shining example is when sunflowers turn to face the sun. Engineers have long been busy trying to replicate this natural phenomenon with a variety of artificial, “smart” materials that respond to an external stimulus, like sunlight. The challenge is how to develop a system to "intuitively" detect and accurately track the direction of the stimulus.
Xiaoshi Qian, a researcher at the University of California, Los Angeles, has developed a breakthrough artificial phototropic system based on nano polymers, as Nature Nanotechnology recently reported. Called SunBOT, which stands for “Sunflower-like Biomimetic Omnidirectional Tracker,” the technology essentially mimics sunflower behavior, which could potentially revolutionize the process of maximizing the efficiency of solar energy capture.
Here are 5 things to know about SunBOT:
1. Each stem has a diameter of approximately one millimeter, and is infused with a nanomaterial that transforms light into heat with a little “flower” coated with solar energy-collecting material.
2. This new polymer system can be used in solar vapor generation devices, enhancing solar energy-harvesting capacity by up to 400%, by catching oblique sunrays.
3. These systems will be able to autonomously and instantaneously detect and track incident light, without any additional power supply or human intervention.
4. SunBOTs bend towards stimuli due to the asymmetric deformation between the illuminated high-temperature region and the shaded low-temperature region, just like the flower!
5. The principle behind SunBOTs is universal and can be extended to many responsive materials and a broad range of stimuli, not only light. As in nature, cells and bacteria can migrate towards sources of chemical gradients, with potential uses in food production, in vitro fertilization, robotics and other environmental applications.
Source: Smithsonian Magazine