ADVERTISEMENT

A Biodegradable Piezoelectric Polymer For Vibration Energy Harvesting Applications

Following the development of portable electronics, the requirement for self-powered electronic devices has emerged as one of the hottest scientific topics for next generation of electronics. One approach to scavenge the energy from the environment is utilizing piezoelectric materials to perform the energy harvesting process.

Normally, poly(vinylidene fluoride) (PVDF) based piezoelectric polymer materials are most common materials used in sensors, transducers, and energy harvesting applications. However, PVDF materials suffer from losing their piezoelectricity when the temperature is above 75℃. PLA is a biodegradable polymer which can be synthesized via ring-opening polymerization using the monomer of lactic acid. The monomer can be produced from sugar and starch by bacterial fermentation. From the previous research results, it was found that processed PLLA exhibits excellent piezoelectric property and can be used for sensors, actuators, and energy harvesting applications.

ADVERTISEMENT

Recently, Ren’s research group in Chinese Academy of Sciences has found that a poly(L-lactic acid) (PLLA) based biopolymer can generate around 10 µW electric power output using double layers of the PLLA films under low-frequency vibration. Additionally, Ren’s group also found that the PLLA polymer even maintained its high piezoelectricity after thermal treatment at 140℃ without an extra-poling step.

At the beginning of the investigation, the PLLA cantilever device was simulated using a theoretical equation which calculated the resonance frequency based on material property and device dimension. The length ratio, thickness ratios between the PLLA layers and the poly(ethylene terephthalate) (PET) layers, and tip loads were calculated to achieve the optimized output conditions and resonance frequency.

Furthermore, a double-layered PLLA based cantilever device was designed and fabricated based on the theoretical result.  After the PLLA films were fabricated by solution casting method, the double-layered PLLA films were sputter coated with Au electrodes on both sides of the film and glued to the top of the PET passive layer using epoxy. A tip load was also attached to the free end of the PET film to form a cantilever structure.

The device was tested using a shaker driven by a function generator and an amplifier. Test results showed that the PLLA based cantilever device generated around 14 µW power for the vibration around ~50 Hz. Next, the output signal was rectified by a lab-designed full-bridge circuit, the rectified PLLA cantilever signal was used to charge an 8 mAhr lithium-ion battery to 3.2 V within 7.5 hours. The electrical energy stored in the lithium-ion battery can light up 30 LEDs for one minute. The paper was published by Advanced Sustainable Systems in 2017.

ADVERTISEMENT

This study, A Poly(l-Lactic Acid) Polymer-Based Thermally Stable Cantilever for Vibration Energy Harvesting Applications was recently published in the journal Advanced Sustainable Systems.

Comments

READ THIS NEXT

Using Physics To Capture The Changes To The Earth System In The Anthropocene

The Anthropocene represents an entirely new epoch in the history of the Earth System. Evidence shows that the evolution of […]

Cost And Resource Implications Of Light-Duty Vehicles In Addressing Climate Concerns

Three interconnected papers (Harvey 2017, 2018a,b) assess (i) the implications for the long-term price of oil when achieving reductions in […]

Deciphering Multiphase Slope Deformation From A Cave’s Perspective

Caves are environments that often act as traps in which time appears to have stopped. Because inactive cave passages are […]

Pyrolysis Behavior Of Multi-Arm Azide Copolymer As Solid Rocket Fuel

A high energy for rocket fuel is one of the main goals pursued by scientists. Azido groups have a positive […]

2018 Spending Bill Drastically Increases Funding For Scientific Research

Scientists and researchers around the United States may have reason to rejoice today, as the US has just passed it’s […]

Function Of The Nucleus

The function of the nucleus is to store a cell’s hereditary material, or DNA, which helps with and controls a […]

Projectile Motion Equations

Grab a baseball and toss it straight up. What happens? As you initially throw the baseball, it will gains some […]

Science Trends is a popular source of science news and education around the world. We cover everything from solar power cell technology to climate change to cancer research. We help hundreds of thousands of people every month learn about the world we live in and the latest scientific breakthroughs. Want to know more?