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Updated: Dec 22, 2025

Fabrication and Characterization of Superconducting Resonators
Published on: May 21, 2016
Design and characterization of an enclosed coaxial carbon nanotube speaker
Suraj Prabhu1, Andrew Barnard1
1Department of Mechanical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931, USAsmprabhu@mtu.edu, arbarnar@mtu.edu.
Abstract:
Automotive mufflers are heavy, large, and loud at low frequencies. Carbon nanotube (CNT) speakers are solid-state, lightweight, flexible, and capable of handling high temperatures. This makes them suitable as loudspeakers in active exhaust noise cancellation applications. A coaxial CNT speaker designed for active noise control in an exhaust system is developed. Test results for resistance, in-pipe axial sound pressure level, and efficiency are presented. The maximum in-pipe sound pressure level was above 120 dB (re 20 μPa) using 105 W of electrical power. The maximum power efficiency was 0.008%. The weight, dimensions, and sound pressure level of the speaker show promise for active exhaust noise cancellation applications.
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