High Efficiency and Anomalous Photoacoustic Behavior in Vertical CNTs Array

• Published in: Energy & environmental materials (Hoboken, N.J.) Vol. 6; no. 1; pp. 105 - n/a
• Main Authors: Li, Jiapu, Wang, Ziyu, Jiang, Laiming, Yu, Zechuan, Ge, Xu, Ouyang, Jun, Yang, Xiaofei, Tian, Xiaobao, Tian, He, Zhu, Benpeng
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.01.2023; School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China%The Institute of Technological Sciences,Wuhan University,Wuhan 430072,China%College of Materials Science and Engineering,Sichuan University,Chengdu 610064,China%School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China%Department of Mechanics,Sichuan University,Chengdu 610065,China%Institute of Microelectronics and Beijing National Research Center for Information Science and Technology(BNRist),Tsinghua University,Beijing 100084,China
• Subjects: anomalous photoacoustic behavior; Arrays; Carbon nanotubes; CNTs array; Energy conversion; Energy conversion efficiency; Forced vibration; Graphene; Musical instruments; Nanotechnology; Nanotubes; Nano‐Helmholtz Cavity; photoacoustic; Sound; sound generator; Sound generators; Sound pressure; anomalous photoacoustic behavior; sound generator; CNTs array; photoacoustic; Nano-Helmholtz Cavity
• ISSN: 2575-0356; 2575-0348; 2575-0356
• DOI: 10.1002/eem2.12253

Miniaturized sound generators are attractive to realize intriguing functions. Thermoacoustic device's application is seriously limited due to the frequency‐doubling phenomenon. To address this issue, photoacoustic sound generator is considered as a promising alternative. Here, based on vertical single‐wall carbon nanotubes (CNTs) array, we introduce a photoacoustic sound generator with internal nano‐Helmholtz cavity. Different from traditional device that generates sound by periodically heating up the open space air around material, this sound generator produces an audio signal by forming a forced vibration of the air inside the CNTs. Interestingly, anomalous photoacoustic behavior is observed that the sound pressure level (SPL) curve has a resonance peak, the corresponding frequency of which is inversely proportional to the CNTs array’s height. Furthermore, the energy conversion efficiency of this photoacoustic device is 1.64 times as large as that of a graphene sponge‐based photoacoustic device. Most importantly, this device can be employed for music playing, bringing a new clew for the development of musical instruments in the future. Here, based on vertical single‐wall carbon nanotubes (CNTs) array, we introduce a photoacoustic sound generator with internal nano‐Helmholtz cavity. Different from traditional device that generates sound by periodically heating up the open space air around material, this sound generator produces audio signal by forming a forced vibration of the air inside the CNTs. Interestingly, anomalous photoacoustic behavior is observed that the sound pressure level (SPL) curve has a resonance peak, the corresponding frequency of which is inversely proportional to the CNTs array’s height.