Knowing the correct vibration frequency is important as it is that frequency that makes it possible to move the particles in the desired direction. Why is knowing the correct vibration frequency important, and how does the vibration frequency affect the direction of the particles? In your research, you used an algorithm to determine the most appropriate vibration frequency for the particles. In other words, we used a feedback loop to adjust the process to accelerate the shape-forming process in a relatively short time, instead of waiting a long time as you would in nature. The nature-inspired algorithm we developed iteratively selects and applies the vibration field associated with different frequencies to gradually drive the particles towards the target shape. The vibration fields set the particles placed on the top of the plate in motion, whose direction and magnitude tend to change drastically from place to place at the same frequency and from the same areas at different frequencies. Similar to the shape formation processes in nature directed by spatially nonlinear external fields, we used spatially nonlinear vibration fields produced on a silicon plate driven by an actuator, also known as a Chladni plate. Our work was not focused on the accurate simulation of natural shaping processes but was rather inspired by them. Can you describe how you carried out your latest research into simulating the natural processes behind these intricate shapes? However, the natural shape formation processes we studied here are not always that intuitive or “one-step” processes and may pass through numerous states on their way. In general, the relation between the template and shape is intuitive.
Researchers often employ sophisticated hardware and processes consisting of dozens or even hundreds and thousands of transducers to produce these templates and make them reprogrammable. These templates would allow particles or building blocks to explore the associated energy landscape and eventually be trapped at the global minimum of the energy. Many researchers have focused on creating a specific template - topographic features, energy wells in acoustic or magnetic fields - in the form of the desired structure or shape. They are also not easily predictable or replicable. The natural phenomena of creating shapes from long term external stimuli are complex and often involve chaotic dynamics. Why have researchers never before attempted to produce these shapes by mimicking natural phenomena? From state to state, the formation is gradually shaped in an unpredictable manner. However, it’s often the external stimuli that can cause certain internal reactions and eventually drive the formed structure out of equilibrium and into a new state. I’m not a geologist, but according to the latest theories, the emergence of these natural formations are usually extremely complex multiphysics processes, consisting of elastic deformations, frictional forces, electrochemistry, microcracks, biogenic factors, etc. How are complex natural formations such as arc-shaped rocks typically formed? These phenomena make us wonder if we can artificially make recognizable shapes similar to the ones found in nature from nonlinear and chaotic energy fields such as the known vibration field on a Chladni plate. Some natural formations, such as sandstone arches and pillars, marble caverns and columns, pyramid-shaped dunes and the famous Badlands Guardian, leave a strong impression of intelligent design rather than the result of a random process.
Complex formations and landforms are gradually produced by long-term external stimuli like wind and water erosion, which act nonuniformly on surfaces and change with time. The biggest source of inspiration was natural phenomena. What inspired your latest research into the natural processes involved in creating complex structures? In their study, Professor Quan Zhou and his team of researchers analyzed naturally occurring phenomena in an attempt to replicate the formation of complex structures.