Computers Math

A ‘best practice’ protocol for researchers developing piezoelectric materials has been developed by scientists — a first in this cutting-edge field of technology.
The protocol was developed by an international team led by physicists at University of Bath in the UK, in response to findings that experimental reports lack consistency. The researchers made the shocking discovery that nine out of 10 scientific papers miss experimental information that is crucial to ensure the reproducibility of the reported work. They discuss the urgent need for a standardised piezoelectricity research protocol in the journal Nano Energy.
Dr Morteza Hassanpour Amiri at the Max Planck Institute for Polymer Research, Germany and first author of the study, said: “Research into piezoelectricity has accelerated in recent years, and for good reason: piezoelectric materials generate electricity when you exert pressure or mechanical vibrations, or when you tap on or distort them. Add a circuit and this electricity can be stored and then used.”
High energy-harvesting efficiency
Because of the huge potential of the piezoelectrics, over the past 20 years a steady stream of new materials and composites have been developed and tested for their energy harvesting potential, with many claiming high efficiencies.
But the researchers, led by Professor Kamal Asadi from the Department of Physics, suggest these findings — sometimes published in high-calibre journals — often do not include details of key experimental parameters. These details are essential to ensure reproducibility when other research teams set out to independently evaluate or further improve the featured materials.

Explaining, Professor Asadi said: “Reproducibility of experimental research findings may not be the key to the success of a research, but it is the key to ruling out unreliable findings from being accepted as fact. The enthusiasm to develop a champion material that shows impressive performance should be accompanied with enough supporting data.”
For the study, the Bath researchers assessed 80 randomly selected research papers published over the past two decades on piezoelectric energy harvesting devices. For nearly 90% of these papers, essential experimental parameters — needed to evaluate materials and devices — were missing, thus rendering the experiments hard, and sometimes impossible, to reproduce.
The importance of reproducibility
Expanding, Professor Asadi said: “There are three important reasons why reproducibility is important: We are scientists and should strive to be as accurate as possible; we have limited resources, so by reporting all the necessary parameters that guarantee reproducibility, we are helping our peers to build up on our findings and advance the field; by being transparent, we also build trust with the public, and with science funding organisations and policymakers, and provide a better guidance for future ‘big’ decisions that can affect us all.”
Professor Asadi, who is a leading expert in piezoelectricity, says this lack of data is hampering progress in the field, as researchers can’t turn to the literature to identify materials with the best harvesting potential, and then further develop these promising materials.

New protocol
The new Bath protocol suggests a standardised data collection and reporting. Professor Chris Bowen from the Department of Mechanical Engineering at Bath, who was also involved in this study, said: “We have basically created guidelines that would be helpful to researchers in their field of piezoelectricity.”
Professor Asadi is hopeful that electronic devices powered by piezoelectricity will be on the market within the next 10 years.
“That’s why it’s important to have a standardised protocol for reporting research data for a quantitative evaluation of energy harvesting materials and devices. Doing so enables scientists to make real progress building on each other’s experiments and working towards a common goal: making piezoelectricity a reality for anyone hoping to charge their devices more sustainably and without reliance on a traditional power source.”
He added: “The field of piezoelectric energy harvesting is a really exciting field, it has lots of potential and great scientists are working on it, but it’s still fledgling, and so to make sure we advance as well and as quickly as possible, ensuring experiments are reproducible is going to be crucial, so I hope our suggested protocol is adopted by the community at large.”
The new protocol is described in the paper “Piezoelectric energy harvesters: A critical assessment and a standardized reporting of power-producing vibrational harvesters.” More

Researchers at the California Academy of Sciences, along with a collaborator at Denison University, have developed an innovative new model to assess how the California economy might have fared without economic closures to slow the spread of the coronavirus pandemic. Their initial findings — published today in Frontiers in Physics — reveal that under a “business-as-usual” approach wherein there were no business closures, California’s economy would have generally been better off than in reality. However, the economic impacts would still have been substantial and unevenly distributed, and there would have been a significant increase in deaths and hospitalizations from COVID-19 exacerbating current inequities.
“There is a common assumption that the economic emergency was caused solely by how we’ve reacted to the pandemic with varying business closures,” says senior author and the Academy’s Curator of Geology Peter Roopnarine, PhD. “So we asked, what if we had not shut down the economy? Ultimately, we found that the economic consequences, while lessened, would have still been severe and unevenly distributed throughout the state.”
The model allows for comparisons of pandemic impacts across regions and economic sectors within California, providing public health experts with location-specific socioeconomic data to develop more effective mitigation and vaccination strategies.
“When you have a pandemic, there will be unavoidable economic and social consequences,” says Roopnarine. “In order to create equitable policies and mitigation strategies that balance these consequences, we need tools that help us understand the varied impacts. This model is now one such tool.”
A California “business-as-usual” case study
Since the start of the pandemic, there had been much debate over how to quell the virus while sparing the economy. Citing record levels of unemployment in the United States, some argued that keeping the economy open — despite the risk of worse health outcomes — would have done less societal harm than the widespread business closures that were implemented. This study shows that may not be the case.

“Earlier, less robust modeling studies incorporated biases that prioritized the market over people’s health,” Roopnarine says. “We show that is a simplistic and dangerous false dichotomy, and the economy would have been impacted even without closures because of dramatically increased mortality.”
Indeed, without any mitigation measures, the researchers estimated that by March 2021, California’s unemployment rate would have reached 5.43% compared to 3.9% pre-pandemic. In reality, the employment numbers from March 2021 showed 8.4% unemployment. However, lower unemployment under that “business-as-usual” approach would have come at a steep price to public health. Without closing the economy, the model estimated nearly 170,000 deaths by March 2021 for just workers alone — more than three times the 52,000 actual cumulative COVID-19 deaths in California during that period.
Though the overall economy would have fared better, not every region would have been spared economic hardship under a “business-as-usual” approach. Of the ten regions studied, two (Fresno and Stockton-Lodi) would have experienced higher unemployment than in reality because they have smaller, less diverse economies, generally older workers, and relatively large agricultural sectors. These economies would have been impacted even more disproportionately by death and illness from COVID than they already have been, potentially leading to more severe cascading unemployment elsewhere.
“These findings imply that the initial mitigation responses, such as business closures, protected these more vulnerable economies from incurring larger job losses by preventing the spread of COVID-19,” Abarca says. “Our results also raise important questions about who benefits the most from our economy under normal circumstances, and how that economy can be improved to better serve those that have been hit hardest by this pandemic and future crises.”
A systems-level look reveals nuanced solutions
Though a paleontologist might seem an unusual candidate to lead a study on the economic effects of a pandemic, Roopnarine sees strong parallels between this work and his typical research analyzing how stressors like mass extinction events impacted prehistoric ecosystems.

“From galaxies to the cells in your body, complex systems have certain features in common,” Roopnarine says. One of these common features is being highly interconnected: what happens in one part of the system manifests in other parts. For a prehistoric environment, this might mean an asteroid decimates plant life resulting in the collapse of the reign of dinosaurs. For the economy, it could mean worker deaths from COVID in the agricultural sector lead to slowed food production and therefore negative impacts on the restaurant industry. It is these kinds of cascading effects on a system that the research team analyzed in this study.
By using data from the United States Bureau of Economic Analysis, the researchers determined the strength of connections between different economic sectors in various regions throughout California, allowing them to measure the susceptibility of each region to negative cascading effects such as those triggered by the pandemic. For public health experts and policymakers working to combat COVID-19 and future pandemics while minimizing economic impacts, this provides a foundation for building more robust mitigation and vaccination responses that target the most vulnerable regions.
“There are clear priorities for vaccination based on age and healthcare workers,” Roopnarine says. “But beyond that, our prioritization appeared to happen in a haphazard manner. Using our model, we can determine which workers are at greater risk of unemployment during a pandemic based on the sector they are in and which sectors are most important to prevent cascading economic damage. In other words, which industries should go back to work sooner to have the greatest health and economic outcomes.”
To ensure that decision-makers can utilize the model, study co-author Joseph Russack has designed an interactive data visualization tool that enables experts to explore the data used in the study, as well as simulate various economic scenarios based on the contagiousness, or R0, of novel COVID-19 variants.
“It’s important that we start applying complex system theory toward pandemic solutions,” says Academy Curatorial Assistant and study co-author Maricela Abarca. “The value of this model is that it shows government leaders that more nuanced approaches are available. We want to balance both the health of the economy and the health of the people participating in it so we can move away from an either/or narrative.” More