Underwater Active Acoustic Energy Harvesting

By Parker Wilmoth
Slide 1: Acoustic Energy Harvesting for Battery-less Underwater IoT — title slide

Slide-1

Acoustic Energy Harvesting For Battery-Less Underwater Iot

Parker Wilmoth, Reu Scholar (The University Of Texas At Tyler)

Jayden Noel, Fau A.D. Henderson

George Sklivanitis, Reu Mentor

Nsf Reu In Sensing And Smart Systems – Fau 2021

Marine And Environment: Cognitive Wireless Radios For Maritime Robotics

Slide 2: Underwater wireless challenges — bullets listing energy requirements, lack of energy sources underwater, short battery lifespan

Slide-2

UNDERWATER WIRELESS CHALLENGES

  • Sending data underwater requires more energy than on land
  • No energy sources (e.g., wind, solar) for sustained underwater operations
  • Batteries have a short lifespan
Slide 3: Our solution: Battery-free underwater IoT — leverage piezoelectric effect, use supercapacitors, exploit acoustic sources to send energy, communicate, localize

Slide-3

OUR SOLUTION: BATTERY-FREE UNDERWATER IOT

  • Leverage the piezoelectric effect — harvest electric energy from sound waves
  • Use supercapacitors instead of batteries
  • Exploit existing and/or dedicated acoustic underwater sources to
    • Send sound energy
    • Communicate
    • Localize
Slide 4: Piezoceramics & energy harvester circuit with two graphs

Slide-4

PIEZOCERAMICS & ENERGY HARVESTER CIRCUIT

  • Piezocylinders — omnidirectional energy collection
  • Compared rubber vs. silicon potting
  • Took impedance measurements to create an electrical equivalent model
  • Prototyped a regulation and sleep circuitry to monitor harvested energy

A photo of a cylindrical device wrapped with wires is placed next to the graph. There is another line graph titled "Impedance of 25kHz Piezo at different frequencies" plotting "Impedance (Ω)" against "Frequency (kHz)". Next to this graph are photos of two containers labeled "A" and "B" for "Silicone Rubber" and a container of "GORILLA" glue. The final visual element is a circuit diagram labeled "Butterworth Van-Dyke Model of Piezo Vibrator" and a photograph of a physical circuit setup on a table with a laptop, breadboard, and other equipment.

Slide 5: Future work - A circuit diagram

Slide-5

FUTURE WORK

  • Build and simulate an impedance matching circuit to minimize energy losses
  • Characterize the amount of energy that we can harvest for
    • Piezoceramics with different resonant frequencies
    • Different input power and range of the acoustic source
  • Dynamically change the impedance load of the piezo and reflect the carrier sound signal at different frequencies —> emulate an underwater FM communication protocol

A circuit diagram with various components like resistors (R1, R2, R3, R4), an op-amp (U1), and an LED, and a software icon for "Multisim". There is also a small screenshot of a measurement device's display showing "3.0189 V".

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For a downloadable version of this presentation, email: I-SENSE@FAU.

Additional Information
The Institute for Sensing and Embedded Network Systems Engineering (I-SENSE) was established in early 2015 to coordinate university-wide activities in the Sensing and Smart Systems pillar of FAU’s Strategic Plan for the Race to Excellence.
Address
Florida Atlantic University
777 Glades Road
Boca Raton, FL 33431
i-sense@fau.edu