What are the key challenges that acoustic textiles face in the coming years?5 answersAcoustic textiles face several key challenges in the coming years. One challenge is to enhance their performance characteristics to be comparable to conventional acoustic materials such as glass fibre mats and polyurethane foams. Another challenge is to minimize the damage inflicted on the environment throughout the whole life cycle of the textile product. Additionally, the electrical performance of textile circuits woven or knitted within a textile matrix presents unusual constraints due to the textile manufacturing process and the properties of the fibers used. Signal attenuation and the ability to form reliable interconnections are major challenges for distributed sensors connected via an electronic fabric. Furthermore, the competitiveness of products such as cars and washing machines is being considered in terms of noise levels, making noise control an important challenge for acoustic textiles.
What material is best for sound absorption?5 answersVarious materials have been studied for their sound absorption properties. Green materials derived from agricultural by-products, such as coconut fiber, kenaf fiber, rice bran, rice husk, rice straw, Hanji, tea-leaf fiber, mandarin peel, pineapple-leaf fiber, corn husk, peanut shell, sugar palm trunk, yucca gloriosa fiber, fruit stones, wood barks, flax fiber, and nettle fiber, have shown promise as sound absorbers. The thickness and density of the material, as well as the presence of an air back cavity, are key variables that determine sound absorption performance. Thicker materials generally exhibit better sound absorption in the low- and mid-frequency range, while higher density is associated with better sound absorption at the same thickness. Increasing the distance between the material and the air back cavity also enhances sound absorption at low frequencies. Therefore, various green materials, including fibers, granules, and porous materials, can be effective sound absorbers if their thickness, density, and air back cavity are properly controlled.
How can sound be formed material?5 answersSound can be formed material by exploring the physical properties of objects and their acoustic principles. By directly interacting with sound-producing objects, new art forms can be created where the morphology of sound is developed in dialogue with the physical objects and the surrounding space. Understanding the underlying acoustic principles of materials such as metal rods and plates allows for the exploration of the timbral possibilities of sound objects and the shaping of their spectra. This approach challenges the traditional perception of sound art and music as immaterial art forms, highlighting the importance of knowledge in both materials and acoustic principles. Additionally, sound absorption materials can be prepared using various methods and materials, such as enclosing inner cotton in a bag-shaped skin material or using non-foaming material slurry to form particles with high sound absorption efficiency. These materials offer high sound absorption performance and can be used in various environments.
How can textile materials be used to create sound absorbers?5 answersTextile materials can be used to create sound absorbers by utilizing their porous structure and specific weave patterns. The porous nature of textiles allows sound to propagate through an interconnected pore network, resulting in sound energy dissipation. Different weave structures, such as plain, twill, and honeycomb, can be employed to enhance the sound absorption properties of woven fabrics. The number and shape of pores in the fabric also play a role in sound absorption performance. Additionally, the characteristics of the yarn used in the fabric, such as texture and twist, can influence its sound absorption properties. The thickness, porosity ratio, and cavity depth of the fabric also affect its sound absorption coefficient. Furthermore, combining woven fabrics with nonwoven textiles or creating air gaps can further enhance the noise reduction efficiency. Overall, textile materials offer a versatile and effective solution for creating sound absorbers.
How can piezoelectric materials be used to harvest and convert acoustic sound energy?5 answersPiezoelectric materials can be used to harvest and convert acoustic sound energy by utilizing their ability to convert mechanical energy into electrical energy. These materials, such as polyvinylidene fluoride (PVDF) and Lead Zirconate Titanate (PZT), have been extensively studied for their potential in energy harvesting applications. PVDF-based piezoelectric generators, inspired by the eardrum and cochlea, have been developed to harvest multi-frequency sound energy, exhibiting high acoustoelectric conversion performance without the need for sound-pressure amplifiers. PZT-based piezoelectric transducers have also been widely researched and are considered the most dominant method for mechanical energy acquisition due to their high electrical and mechanical constants, large electromechanical coupling coefficients, and low losses. By optimizing the structure and vibration frequency relationship, piezoelectric transducers can efficiently convert sound vibrations into electrical energy, making them suitable for various applications, including self-powered acoustic sensors and low-power supply devices.
How do wood acoustic panels absorb sound?5 answersWood acoustic panels absorb sound through various mechanisms. One approach is to use materials such as chips and sawdust of red and beechwood, which have different particle sizes and thicknesses to enhance the absorption coefficient. Particle sizes in the range of 0.31 mm to 2.5 mm show better absorption, while sizes equal to or higher than 5 mm to 8 mm and sizes below 0.16 mm are less efficient. Another method involves combining a sound-absorbing sheet and a honeycomb structure. The sound-absorbing sheet, with a specific air flow resistance, allows for the combination of membrane vibration and sound reciprocation through micropores, resulting in improved sound absorption performance. Additionally, the use of a protection layer made of paint with synthetic resins dispersed in water can reinforce the sound-absorbing body of the panel. These different approaches contribute to the effective absorption of sound by wood acoustic panels.