Development of an Acoustic Pressure Sensor for Low-Amplitude an‎d Low-Frequency Applications

1/26/2027 12:00:00 AM

The detection of low-amplitude an‎d low-frequency acoustic noise in underwater environments poses a significant challenge due to high signal attenuation, background noise interference, an‎d limited performance of conventional sensors. In this research, a resistive acoustic pressure sensor was designed an‎d developed to provide a practical solution for detecting pressures below 3 Pa an‎d infrasonic frequencies (below 14 Hz). Chapter 1 introduced the research problem, objectives, an‎d the critical need for low-frequency, low-pressure sensors in various fields such as communication, medical technologies, an‎d defense. Despite their importance, this area has received limited attention. In Chapter 2, a comprehensive literature review was conducted, an‎d among various sensing mechanisms, the piezoresistive method was selec‎ted due to its linear response an‎d high gain performance in the low-frequency range. In Chapter 3, a conceptual design an‎d numerical modeling were conducted. A graphene-PDMS-based nanocomposite sensing structure was developed using a laser-engraved graphene (LEG) technique on a polyimide substrate. Two configurations of the sensor— with an‎d without a reinforcement layer—were designed an‎d fabricated. A Rosette-patterned resistive layout was implemented to optimize strain response. Chapter 4 focused on the design an‎d fabrication of calibration an‎d measurement setups, particularly for dynamic pressure assessment. Experimental results from static an‎d dynamic tests, including tensile, hysteresis, cyclic stability, an‎d sinusoidal pressure response, were analyzed. The baseline sensor exhibited a sensitivity of 61.00 mV/V/kPa, a non-linearity of 0.8%, an‎d a hysteresis of 0.22%. The reinforced configuration showed improved sensitivity (67.28 mV/V/kPa) but also exhibited increased hysteresis an‎d non-linearity. Chapter 5 provided a comprehensive conclusion, highlighted the innovations, an‎d presented recommendations for future research. Overall, the proposed sensor demonstrates stable behavior, reliable response, an‎d the potential for practical implementation in underwater low-pressure an‎d low-frequency acoustic monitoring applications.

سنسور فشار آكوستيكي , فروصوت , نانوكامپوزيت گرافن-PDMS , پيزومقاومتي , حكاكي ليزري

Acoustic Pressure Sensor , Infrasound , Graphene–PDMS Nanocomposite , piezoresistive , Laser engraving

Shiri

Dr.Nouri_ Dr.Rriahi