Biomimicry is the emulation of various models and systems found in nature for the purpose of solving complex human problems. At Bimitech we call this biomimetic technology. Learn more at the Biomimicry Institute.
Lessons from the world’s most efficient flyer
After millions of years selection and evolution, flyers like hummingbirds and insects have evolved to have a near perfect system of flight and aerodynamic efficiency. Research has found that most hummingbirds are about 25% more efficient than the best drones developed to date.
Unlike any other bird’s wings, hummingbirds flap their wings in much the same way as insects do. This means their wings rotate around their long axis during transitions between upstrokes and downstrokes. This design enables their hyper-efficient displacement of air.
The core innovation of Bimitech’s biomimetic cooling technology is the introduction of a flapping membrane, or biomimetic “wing”.
Current problems facing traditional rotary fan-based cooling solutions
Due to copper motors and stators.
Overall efficiency is about 30%.
2-3 year lifespan. Require maintenance.
High RPM creates high frequency noise levels.
Computational Fluid Dynamics (CFD) simulations in conjunction with experimental measurements have been used to optimize various design parameters such as size, aspect ratio and angle of attack. “Clap and fling” flow rate mechanisms have also been investigated ensuring the fan has the highest aerodynamic efficiency. Additionally, energy loss has been minimized due to the lack of friction from traditionally used ball bearings. The fan is powered by a piezo actuator with high electrical-mechanical energy conversion. The piezo actuator generates almost zero heat during operation, allowing the fan to achieve up to 2x more overall efficiency.
Removing the “dead air zone”
A typical rotary fan has a hub at its center where the motor resides and which the blades rotate around. This creates a “dead air zone” in the center of the fan without any air flow, resulting in the hottest region of the heat sink in many applications.
In our biomimetic fans, the air profile is uniform due to the single flapping wing design. This results in no “dead air zone”. The design can be further customized higher air flow velocity and better efficiency.
Our biomimetic fans contain no motors, which result in no motor-generated noise. In a traditional rotary fan, noise pitch is principally proportional to the number of blades present. As the biomimetic fan contains only a single “blade” (wing), the frequency of the noise generated is lower, resulting in a lower tone of noise. This lower tone noise is more comfortable to the human ear.
A unique and powerful advantage to our piezoelectric fans is that no electromagnetic field is generated during operation. Unlike regular fans, air displacement in our piezo fans is generated through vibration of a piezo layer, rather than a motor. The result is a cooling solution – comparable in efficacy to that of a rotary fan – without the presence of electromagnetic waves.
This unique feature of Bimitech’s piezo fans has two distinct benefits: firstly EMFs produced by the fan (none) do not impact EMFs present in the application needing to be cooled. Secondly, the EMFs in the application do not adversely affect the fan, increasing longevity.
An EMF-free cooling solution has significant impact on applications sensitive to electromagnetic interference. An example of this is electro microscopy, where any EMF interference is detrimental to the performance of the application, and thus cooling has always presented a problem. Currently passive cooling (natural convection) is used for electro microscope applications, which limits the input power.
Unlike a traditional rotary fan, the biomimetic fan consists of only a few simple components. There are no moving parts, no bearings, oil leakages or maintenance required. It is powered by our ultra reliable Python actuator.
Designed with aerospace grade lightweight materials, there are no motors present in our biomimetic fans. This makes the biomimetic fan up to 5x lighter than a traditional rotary fan of similar cooling capacity.
Our biomimetic fan does not require the restrictive round format present in rotary fans. Its shape can be flexibly customized to fit specific applications and optimized according to the required form factor. In addition, multiple fans can be used in parallel.