IIT Hyderabad researcher develops a noise-controlling sheet absorber by mimicking bee hives

Acoustic energy is dissipated to low frequency ranges by sound-absorbing panels made of paper and polymer honeycomb, according to an Indian researcher. Environmental noise control and building acoustics can both benefit from the technology. Understanding the physics of beehive sample acoustic energy dissipation and then mimicking its design are key components of biomimetic design methodology. At this point in time, the technology is TRL 6, and he intends to scale up his demonstration with Eaton PVT Ltd’s assistance.

Key Highlight:

• Acoustic energy is dissipated to low frequency ranges by sound-absorbing panels made of paper and polymer honeycomb.
• The technology can be applied to both building acoustics and noise control in the environment.
• At this point in time, the technology is TRL 6, and he intends to scale up his demonstration with Eaton PVT Ltd’s assistance.
• According to Dr. B. Venkatesham, low-frequency applications could open up a 15% market share opportunity for traditional sound- absorbing acoustic materials.
• For this project, the design methodology calls for first understanding the physics of how sound waves dissipate in bee hives, then taking cues from that design.

Paper honeycomb and a more durable polymer honeycomb structure developed by an Indian researcher serve as sound-absorbing panels that dissipate acoustic energy at low frequencies. The technology can be applied to both building acoustics and noise control in the environment.

It’s been discovered that many conventional materials are effective at controlling higher frequencies.

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Natural bee hives, on the other hand, have been found to be effective at controlling both high and low frequencies due to their geometrical design. acoustical energy was found to be converted into vibrational energy through theoretical and experimental investigation. By virtue of the wall’s damping property, this vibration energy dissipates as heat instead. By using engineering to mimic this property, noise pollution could be reduced at a lower cost.

Faculty at IIT Hyderabad’s Mechanical and Aerospace Engineering Department, Dr. B. Venkatesham and Dr. Surya, created biomimetic acoustic panels with low-thickness and high strength to mimic this property. For this project, the design methodology calls for first understanding the physics of how sound waves dissipate in bee hives, then taking cues from that design. The researchers created a mathematical model, ran optimization calculations on the parameters, and then used that model to create the test samples under carefully controlled conditions. This was followed by the production of a large sample. They’ve taken two different approaches and built their own prototype machines from scratch using two different types of materials, respectively. Prototype machines are being developed for polymer honeycomb structures using the hot wire technique and indexed-Honeycomb Before Expansion (HOBE) processes for paper honeycomb structures.

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For the panels, engineers used an electric knife to slice extruded polypropene straws stacked on top of one another. This is accomplished by using a hot wire to slice the straws, which also serves as a bonding agent. The new technology offers an acoustic energy dissipation mechanism with reduced panel thickness and increased specific strength. Large samples’ absorption coefficients have been measured using a test facility built as part of this project as well.

In the 6th stage of Technology Readiness Level, this technology is supported by the Department of Science & Technology (DST), Government of India, and Dr. B. Venkatesham has partnered with Eaton PVT Ltd, Maharashtra Industrial Development Corporation Kharadi Knowledge Park, Pune. After scaling up the technology demonstration, he intends to make polymer materials in a batch production machine and use newer, self-damping alternatives while also meeting other safety requirements like flame retardance and weather resistance. According to Dr. Venkatesham, low-frequency applications could open up a 15% market share opportunity for traditional sound-absorbing acoustic materials.