SBIR-STTR Award

The conventional approaches to acoustic arrays limit their usage in acoustic reconnaissance for Army applications due to large size and rigid packaging. An acoustic array on a flexible substrate and composed of microfabricated sensors provides a solution for applications where limited size and non-planar surfaces have prevented use of array-based solutions. The primary objective of this research is to develop microelectromechanical systems (MEMS)-based array technology for use in a flexible, conformal, compact acoustic array. Our proposed approach is to leverage recent advances in piezoelectric MEMS microphones, hybrid packaged with low-noise instrumentation amplifiers, mounted onto a flexible, conformal substrate and protected by a metamaterial-enhanced, flexible cover. The stated program goals necessitate an extensive feasibility study of the individual components to determine current readiness level, expectations for future performance and satisfaction of platform and system constraints.

Keywords:
Acoustic Array, Mems-Based

For military applications, acoustic arrays can provide target signatures and locations of aircrafts, vehicles, weapons and personnel. Additional benefits of arrays include immunity to jamming, low cost, low weight and low power consumption. Acoustic beamforming using conventional arrays typically require 10~100s of microphones and have an aperture size ranging from several inches to several feet. Conventional acoustic arrays have seen limited usage in aerial reconnaissance for Army applications due to the size requirements for beamforming. While the size requirements for beamforming is somewhat constrained by the aperture, the array size can be miniaturized by microfabricated microphones and made conformal to a curved surface through the use of a flexible substrate. Our proposed solution is to implement an acoustic array design for broadband using microelectromechanical systems (MEMS)-based, piezoelectric microphones mounted on a compact, flexible substrate. Additional features of the array include a hybrid electronics packaging for signal conditioning and acoustic metamaterials for array performance enhancement. The development of a compact, flexible acoustic array is ideal for small UAS platform where conventional acoustic arrays are impractical.

Keywords:
MEMS, Piezoelectric Microphone, Beamforming, Acoustic Array, Flexible Circuit, Acoustic Metamaterial, Reconnaissance