A team of researchers has created a polymer film filled with chalcogenide perovskite compound that generates electricity when stressed. This phenomenon is known as the piezoelectric effect, which is simply the ability of certain materials to generate an electric charge when mechanical stress is applied.
The piezoelectric effect occurs in materials that lack crystal structural symmetry. Crystals, ceramics, polymers, and biological matter such as bone, DNA, and various proteins are different kinds of piezoelectric materials.
Such materials have the potential to collect the energy related to mechanical vibrations. The best thing about this form of energy is that it is present all around us in abundant supply and is renewable in nature.
However, as the latest research notes, piezoelectric materials that are best performing tend to have the chemical element lead (Pb), which can cause cancer, increase the risk of brain tumors, and hinder DNA repair.
Materials that contain lead are hazardous, and regulators have curtailed their use to protect the environment.
Given the toxicity of lead, which is a heavy, malleable, naturally occurring metal with a relatively low melting point, it is being increasingly phased out of materials and devices.
Hence, the team’s goal was to create a material that was lead-free and able to be made inexpensively using elements that are commonly found in nature.
So, the team from the Rensselaer Polytechnic Institute (RPI) made use of a material that not only does not contain lead but is also one of the few high-performing ones. Hence, it is a great candidate for use in biomedical applications, machines, and infrastructure.
The lead-free material that the team used belongs to the chalcogenide perovskite family exhibiting piezoelectricity. BaZrS3 was the composition used in the study, which is reported to have a pronounced piezoelectric response.
Chalcogenide perovskites have been gaining a lot of attention and advances lately. This family of compounds is related to perovskite structures, which have many favorable properties such as low toxicity, high stability, direct band gaps, good carrier transport abilities, and strong light absorption.
These properties make perovskites really stand out in applications like photovoltaics, photodetectors, light-emitting devices, and photocatalysts.
Interestingly, most high-performing piezoelectric materials are non-centrosymmetric and hence display intrinsically high polarizability. However, many oxide perovskites, including the one used in the study, exhibit a centrosymmetric crystal structure, which is weakly piezoelectric in its pristine form. These compounds are actually non-polar because they inherently lack a net dipole moment.
The dipole moment is the scientific name for the way piezoelectric materials perform when under stress, which is deformation in a way that causes positive ions and negative ions in the material to separate. This dipole moment can be harnessed and turned into an electric current.
But with no net dipole moment, how did the team achieve piezoelectricity? Well, they leverage the loose packing within the chalcogenide perovskite structure to overcome the problem.
Scaling the Technology for Green Energy Applications
The latest study details that despite being centrosymmetric, lead-free chalcogenide perovskite materials become polarizable very quickly when it is deformed. This is due to a loosely packed unit cell, which has a lot of vacant space.
This significant volume of empty space allows extended displacement of ions, which, in turn, allows for the reduction of symmetry and results in an amplified displacement-mediated dipole moment.
The team performed a piezoresponse force microscopy (PFM) on BaZrS3 to confirm the piezoelectricity of the material.
PFM is a functional atomic force microscopy (AFM) model that has been recognized for the unique information it offers on the electromechanical properties of various materials on the nanometer scale.
Structural symmetry in the chalcogenide perovskite material, as per the team, can be easily broken under stress, which leads to an enhanced piezoelectric response. So, once confirmed, the team developed composites of BaZrS3 particles dispersed in polycaprolactone.
The new material synthesized contains barium, zirconium, and sulfur, which were then used to harvest energy from human body motion and power electrochemical and electronic devices.
The team tested the material’s ability to generate electricity by subjecting it to bodily movements like running, walking, tapping fingers, and clapping. The electricity produced during the experiment was found to be enough to power LED banks, spelling out RPI.
“We are excited and encouraged by our findings and their potential to support the transition to green energy.”
– Nikhil Koratkar, Study co-author
The material, according to him, converts mechanical energy into electrical energy. According to Koratkar:
“The greater the applied pressure load and the greater the surface area over which the pressure is applied, the greater the effect.”
The energy harvesting film created by the team is just 0.3 millimeters thick and can be integrated into various machines, devices, and structures like buildings and highways to produce electricity when they vibrate, or vehicles drive over them.
The tests conducted by the team also show that the technology can be useful in a myriad of ways, including in a device worn by bikers or runners that lights up helmets or shows to make them more visible.
Having said that, currently, it’s just a proof of concept. The team hopes to “eventually see this kind of material implemented at scale, where it can really make a difference in energy production,” Koratkar said.
Now, in the next steps, the researchers will inspect the whole family of chalcogenide perovskite compounds to find a material that shows a more powerful piezoelectric effect. For this, the team will make use of artificial intelligence (AI) and machine learning (ML).
“Sustainable energy production is vital to our future,” said Shekhar Garde, Ph.D., dean of the RPI School of Engineering, while applauding the RPI team’s efforts in materials discovery that he says “can help address a global problem.”
The Transformative Impact of Piezoelectricity
Piezoelectricity was first identified by Jacques and Pierre Curie in 1880, and today, the phenomenon is widely used in real-world applications. Their ability to directly convert electrical and mechanical energy makes them highly attractive for applications like energy harvesting devices.
One of the most common examples of piezoelectricity is electric lighters. As you push a button, the lever of the spring hits piezoelectric crystals, and this mechanical stress creates an electrical current, which then travels as a flame to ignite the gas. You can find examples of piezoelectricity everywhere in your daily life.
As we have detailed in our previous article, piezoelectricity has actually become a fundamental principle being used in modern technology, ranging from cell phones and wearable devices, dampening systems, and cleaning solutions to aerospace, sonar, healthcare diagnostic tools, and actuators.
Given its vast usage, several advancements have taken place in their field. It all started with the development of the popular piezoelectric ceramic PZT (lead zirconate titanate) about half a century ago and then Polyvinylidene fluoride (PVDF) in 1964.
Since then, researchers have been working on developing new materials and technologies to improve the efficiency and versatility of piezoelectric devices. One major focus has been on creating environmentally friendly alternatives to lead-based ceramics like PZT due to growing concerns about lead toxicity, as we saw in the above-mentioned study.
Researchers have been exploring materials such as barium titanate (BaTiO₃) and potassium sodium niobate (KNN) for this, which offer piezoelectric properties without the harmful environmental impact of lead.
Additionally, advancements in polymer-based piezoelectric materials like PVDF and its copolymers have allowed for their integration into smart textiles, sensors, and medical implants.
Piezoelectric polymers have actually been extensively investigated for energy harvesting due to their intrinsic flexibility and compliance, which makes them suitable for applications where the device has to undergo a lot of bending to be integrated into wearable devices.
Wearable electronics represent the innovation of traditional rigid electronics, offering revolutionized solutions in healthcare, energy, neuroscience, metaverse, and sustainability. The use of piezoelectricity in these devices allows companies to reduce the need for frequent charging and batteries, offering users the convenience of a portable device along with improved safety.
Recent developments in nanotechnology have also allowed the creation of nanostructured piezoelectric materials, which offer enhanced performance at reduced sizes.
For instance, quantum dots, nanowires, and graphene are being looked into for their potential to significantly improve the sensitivity and efficiency of piezoelectric systems, which makes them really beneficial in applications like flexible electronics and next-gen imaging technologies.
All these innovations in piezoelectric materials have opened new possibilities in various industries, and as these advancements continue, the global market for piezoelectric materials is set to experience significant growth.
Click here to learn how piezoelectric Power Converters help shrink printed circuit boards.
A Massive Growth Ahead
When it comes to the global piezoelectric materials market, it is expected to grow from $1.52 billion in 2024 to $2.19 billion by 2032.
While restricted operations of crucial end-use industries like the electronics and automotive sectors critically impacted the demand for piezoelectric materials, COVID-19 saw a spike in demand for equipment such as oximeters, pyrometers, electronic thermometers, and automated ventilators, which utilize piezo materials to convert one form of energy to another. This then impacted the demand for these materials during the crisis, noted the report on Piezoelectric Materials Market.
Regionally, the U.S. market, in particular, is projected to grow significantly, reaching an estimated value of $248.48 billion in the next eight years, driven by the growing production of electronics, IT, and Telecom sectors. The country’s extensive space exploration program will also contribute to this growth.
Meanwhile, the Asia Pacific market size accounts for $0.99 billion, having a market share of 68.28% in 2023. This domination is due to Asia Pacific emerging as a manufacturing hub for electronics and consumer goods with China, Japan, Taiwan, India, and South Korea focusing on expanding their production capabilities.
While the piezoelectric materials market in Latin America is in its infancy, increasing demand has been observed in the Middle East and Africa due to the region’s expanding healthcare and electronics industry.
In terms of application, the piezoelectric material market is segmented into sensors, resonators, generators & transformers, actuators, transducers, SONAR, acoustic devices, motors, and others.
Among these, the sensors division is projected to expand at a substantial CAGR due to the technology’s application in multiple fields, including consumer electronics, manufacturing lines, and automatic vehicles.
Meanwhile, actuators, which convert electrical signals sent by the system into mechanical energy for control in order to perform a specific action, are expected to account for the largest piezoelectric materials market share, driven by its application in robotic arms, precision control of industrial machining tools, and vehicle braking and acceleration systems.
Consumer goods like microwaves, TVs, washing machines, and remote-controlled toys, which use piezo materials for controlling and working these products, are expected to maintain their lead in the global market. Trailing behind is the automotive industry, which is projected to grow at a stable CAGR.
Companies Utilizing Piezoelectric Technologies
Now, when it comes to companies advancing this field, we’ve got USound, whose MEMS speakers utilize the piezoelectric effect, and Noliac, which develops piezo actuators, generators, and transformers.
Kinetic Ceramics is yet another one whose specialties include piezoelectric actuators, piezoelectric valves, solid-state pumps, precision machining, intelligent systems, and movement control systems.
Amphenol Corporation’s Piezo Technologies (APH +2.42%) also specializes in piezoelectric ceramic materials and ultrasonic transducers. Its products also include devices, assemblies, and systems that are used in aerospace, defense, automotive, transportation, and civil engineering.
CTS Corporation (CTS -0.34%) manufactures piezoelectric products across the med-tech, aerospace, and industrial sectors. The $1.43 billion market cap company’s shares are currently trading at $47.21, up 7.93% year-to-date (YTD). It has an EPS (TTM) of 1.77 and a P/E of (TTM) of 26.66, while it pays a dividend yield of 0.34%.
CTS Corporation (CTS -0.34%)
L3Harris Technologies (LHX +0.36%)
This company provides end-to-end technology solutions that connect the air, space, land, sea, and cyber domains. It also designs piezoelectric ceramic shapes for various applications in the fields of military sonar and acoustics, medical imaging, cancer therapy, and energy harvesting. L3Harris boasts over 70 years of material science expertise in formulating high-performance piezoelectric ceramics, including PZT, PT, and PMN materials for both military and commercial customers.
The company’s piezoelectric ceramic powder formulations are uniform, high-performance, fine-grain, and high-density, which makes them suitable for a broad range of uses, including transducers and highly customized materials that support cancer treatment, drug delivery, imaging, and wound care. Piezoelectric ceramics from L3Harris harvest energy from pressure or vibration that otherwise would be wasted, as such helping reduce reliance on batteries by providing power for wireless sensor networks.
L3Harris Technologies, Inc. (LHX +0.36%)
At the time of writing, LHX shares have been trading at $248.15, up 17.82% this year so far, which puts its market cap at $47 billion. With that, the company’s EPS (TTM) is 6.25 and a P/E (TTM) of 39.72 while paying a dividend yield of 1.87%. While L3Harris Technologies will release its Q3 2024 financial results in the coming days, for 2Q24, the company reported a revenue of $4.5 billion, an increase of 13%, while its operating margin was 9%.
“We delivered another strong quarter of financial results with improved margins, reflecting our commitment to operational excellence and a relentless focus on execution that delivers value to our customers and shareholders.”
– CEO Christopher E. Kubasik
Conclusion
From street lights powered by the traffic to floors capable of powering the building’s lighting to tires charging a vehicle, piezoelectric materials have the potential to revolutionize the clean energy sector. However, even these materials are not without challenges, hence the development of lead-free piezoelectric materials.
These new materials, like chalcogenide perovskites, mark a significant advancement in sustainable energy harvesting technologies. With their low toxicity, high stability, and enhanced piezoelectric response under stress, they can help truly realize the potential of piezoelectric materials and revolutionize energy generation. And as researchers continue to explore these new materials by utilizing AI, this field can pave the way for innovations in biomedical devices, infrastructure, and wearable technology in a sustainable manner.
Click here to learn how advances in piezoelectric composites allow harnessing and interpretation of kinetic energy.
