It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Thursday, September 21, 2023
Efficient next-generation solar panels on horizon following breakthrough
A scientific breakthrough brings mass production of the next generation of cheaper and lighter perovskite solar cells one step closer thanks to researchers at the University of Surrey’s Advanced Technology Institute (ATI).
A nanoscale ‘ink’ coating of aluminium oxide on metal halide perovskite improves the potential of this emerging photovoltaic technology and stabilises the drop in energy output which currently plagues perovskite technology.
Hashini Perera, lead author of the study at the University of Surrey said:
“In the past, metal oxides have been shown to either benefit or degrade the performance of perovskite solar cells. We’ve identified aluminium oxide which can improve performance and minimises the drop in efficiency during conditioning of perovskite solar cells. We show that this nano-oxide allows a uniform coating of perovskite material on highly promising organic molecules that self-assemble on a surface and improve device output.”
Dr Imalka Jayawardena, from the University of Surrey’s Advanced Technology Institute said:
“Performance limits of traditional solar cells are why researchers are switching to examining perovskite as the next-generation solar technology, especially as applications both terrestrial and in space are rapidly growing. Our key development in solar panel technology shows a cost-effective approach to scaling of perovskite solar cells, a development which could help countries around the world to reach their net zero targets faster.”
Prof. Ravi Silva, corresponding author from the ATI, University of Surrey said:
“Solar and wind energy costs are rapidly decreasing based on technology improvements, to the level where worldwide over 80% of all new additional power generation capacity is based on renewables. The levelised cost of solar electricity is now cheaper than most other power generating sources. With the maturing of perovskite solar modules, the levelised cost of electricity will significantly decrease further, and that is why this is such an exciting area to work.”
The research was published in the journal RRL Solar.
The University of Surrey is a leading research institution that focuses on sustainability to deliver impacts that benefit society and help deal with the many challenges of climate change. Surrey is also committed to improving its own resource efficiency on its campuses in Guildford and aspires to be a sector leader. It has set a commitment to be carbon neutral by 2030. In April, it was ranked 55th in the world by the Times Higher Education (THE) University Impact Rankings which assesses more than 1,400 universities' performance against the United Nations' Sustainable Development Goals (SDGs).
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Notes to Editors
Dr Imalka Jayawardena and Hashini Perera are available for interview upon request
Contact the University press office via mediarelations@surrey.ac.uk
Modification of Hydrophobic Self-Assembled Monolayers with Nanoparticles for Improved Wettability and Enhanced Carrier Lifetimes Over Large Areas in Perovskite Solar Cells
Young children do better at school if their dads read and play with them
Fathers can give their children an educational advantage at primary school by reading, drawing and playing with them, according to a newly published report.
Research led by the University of Leeds has found that children do better at primary school if their fathers regularly spend time with them on interactive engagement activities like reading, playing, telling stories, drawing and singing.
Analysing primary school test scores for five- and seven-year-olds, the researchers used a representative sample of nearly 5,000 mother-father households in England from the Millenium Cohort Study - which collected data on children born 2000-02 as they grew up.
According to the research, dads who regularly drew, played and read with their three-year-olds helped their children do better at school by age five. Dads being involved at age five also helped improve scores in seven-year-olds' Key Stage Assessments.
Dr Helen Norman, Research Fellow at Leeds University Business School, who led the research, said: “Mothers still tend to assume the primary carer role and therefore tend to do the most childcare, but if fathers actively engage in childcare too, it significantly increases the likelihood of children getting better grades in primary school. This is why encouraging and supporting fathers to share childcare with the mother, from an early stage in the child’s life, is critical.”
Dads’ involvement impacted positively on their children’s school achievement regardless of the child’s gender, ethnicity, age in the school year and household income, according to the report.
There were different effects when mums and dads took part in the same activities – the data showed that mums had more of an impact on young children’s emotional and social behaviours than educational achievement.
The researchers recommend that dads carve out as much time as they can to engage in interactive activities with their children each week. For busy, working dads, even just ten minutes a day could potentially have educational benefits.
They also recommend that schools and early years education providers routinely take both parents' contact details (where possible) and develop strategies to engage fathers – and that Ofsted take explicit account of father-engagement in inspections.
This study shows that even small changes in what fathers do, and in how schools and early years settings engage with parents, can have a lasting impact on children's learning. It's absolutely crucial that that fathers aren't treated as an afterthought.
Andrew Gwynne MP, Chair of All-Parliamentary Party Group on Fatherhood
The research was funded by the Economic and Social Research Council (ESRC) and led by Dr Helen Norman, Research Fellow at Leeds University Business School, in collaboration with co-author Dr Jeremy Davies, Head of Impact and Communications at the Fatherhood Institute, and co-investigators at the University of Manchester.
Dr Jeremy Davies, Head of Impact and Communications at the Fatherhood Institute, who co-authored the report, said: “Our analysis has shown that fathers have an important, direct impact on their children’s learning. We should be recognising this and actively finding ways to support dads to play their part, rather than engaging only with mothers, or taking a gender-neutral approach.”
Andrew Gwynne MP, Chair of the All-Party Parliamentary Group on Fatherhood, said: "This study shows that even small changes in what fathers do, and in how schools and early years settings engage with parents, can have a lasting impact on children's learning. It's absolutely crucial that fathers aren't treated as an afterthought.”
The final report was launched on Wednesday 20 September with an online webinar. Dr Norman and Dr Davies were joined by a panel of parental engagement experts and dads to talk about the study.
The research project was also co-investigated by Professor Mark Elliot (Professor of Social Statistics at the University of Manchester) and Professor Colette Fagan (Vice-President for Research at the University of Manchester).
IMAGE: EXTENT OF SIMULATED EDZ AND DISTRIBUTIONS OF DAMAGE MODES AROUND NICHE AT END OF EXCAVATION ANALYSIS.view more
CREDIT: SHO OGATA, HIDEAKI YASUHARA
To ensure the effectiveness of high-level radioactive waste (HLW) disposal facilities, the distribution of hydraulic and mechanical properties within the surrounding rock mass, acting as a natural barrier, should be evaluated. To achieve this, it is essential to predict the distribution of the excavation damaged zone (EDZ), which forms due to the creation of multiple fractures during the excavation of the radioactive waste disposal cavity. This is because such a zone is expected to cause an increase in permeability and a decrease in the stiffness and strength of the rock mass.
For precise prediction of the unknown EDZ distribution in specific underground conditions, a numerical analysis should be used. This analysis should have a proven track record of replicating EDZ trends observed in pre-in-situ tests conducted under similar conditions. To enhance reliable predictions for EDZ distribution in HLW disposal projects worldwide, it is advantageous to compile well-calibrated numerical analysis examples from representative underground research areas in each country, such as underground research laboratories (URLs). In the case of one of Japan's prominent research sites, the Horonobe URL, however, there have been limited attempts to replicate EDZ trends through numerical analysis.
In a recent study published in the KeAi journal Rock Mechanics Bulletin, Assistant Professor Sho Ogata of Osaka University and Professor Hideaki Yasuhara from Kyoto University introduced a novel numerical analysis. This analysis successfully replicates the observed EDZ trends resulting from niche excavation within the Horonobe URL gallery at a depth of 350 meters.
“Our findings indicate that the simulated results not only closely align with the measured EDZ data in terms of extent, but also accurately depict the fracture failure modes observed during in-situ examinations,” explained Ogata. “A key factor contributing to this high level of reproducibility compared to measured results is the advanced capability of their numerical analysis to concurrently solve rock deformation and fracturing.”
Their approach addresses the simultaneity of two way interaction between rock deformation and fracture generation, a vital aspect often overlooked in conventional numerical analyses dealing with rock fracture generation. Not solving this interaction completely simultaneously can result in deviations from the actual mechanical responses of rocks during excavation.
“Considering that sedimentary rocks, particularly mudstone, constitute a significant portion of Japan's geological landscape, this numerical investigation of the Horonobe URL, where mudstone prevails, holds substantial relevance and applicability in assessing the viability of geological disposal of high-level radioactive waste (HLW) in Japan,” added Yasuhara.
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Contact the author: Sho Ogata, Center for Future Innovation, Graduate School of Engineering, Osaka University, Japan, ogata@civil.eng.osaka-u.ac.jp
The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 100 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).
Numerical simulations for describing generation of excavation damaged zone: Important case study at Horonobe underground research laboratory
COI STATEMENT
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
The Tibetan Plateau bridge: Remote climate effects of extratropical and tropical forcing
INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES
IMAGE: SNOWY MOUNTAINS OVER THE TIBETAN PLATEAU DURING SUMMER IN 2023view more
CREDIT: CREDIT BY JIANG JILAN
The Tibetan Plateau (TP), which is located in the subtropics of eastern Eurasia, could act as a bridge spanning from the mid-to-high-latitude forcing on the tropical climate, as well as from the tropical region to subtropical systems. Knowledge of the TP bridge and its role in climate variability has advanced over the past several years.
Recently, in a paper published in Atmospheric and Oceanic Science Letters, scientists from the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, and the School of Atmospheric Sciences at Sun Yat-sen University, reviewed recent advances in the bridging roles of the TP in terms of the remote influence of circulation anomalies over the North Atlantic Ocean on Asian monsoon and El Niño–Southern Oscillation (ENSO) events, and in a clear link between the tropical oceans and Asian climate anomalies.
“The winter–spring North Atlantic tripole pattern of sea surface temperature anomalies significantly affects the seasonal transition of the South Asian monsoon and the triggering of ENSO events on the interannual timescale. A distinct negative sensible heating–baroclinic structure in May over the TP provides an intermediate bridging effect in this Atlantic–Asian-Pacific connection, as shown in the figure,” explains the second author of the study, Dr. YU Wei, who then adds: “The TP also plays an intermediate role in the process of the summer North Atlantic Oscillation affecting the East Asian summer monsoon.”
“The suppressed TP convection plays a crucial bridging role in the influence of Maritime Continent convection on extreme drought over Southeast China”, says JIANG Jilan, corresponding author of the study.
Another member of the team, Dr. MA Tingting, also says: “The tropical ocean or the midlatitude quasi-bicycle wave train affect the intraseasonal variation in extreme precipitation in East China through the intraseasonal variation of high potential vorticity systems and surface sensible heating over the TP.”
“The TP will continue to play unique roles in the warming of the global climate,” emphasizes Prof. LIU Yimin, the first author of the study. “However, collaborative efforts are still needed as we strive to move forwards with observing, simulating, and ultimately better understanding the climatic roles played by the TP and the underlying dynamic mechanisms involved.”
JOURNAL
Atmospheric and Oceanic Science Letters
New research brings greater understanding of Asian winter monsoon
Scientists have discovered a new technique which will shed light on the phenomena of winter monsoons – the heavy autumn and winter rainfalls which can cause floods and landslides across southeast Asia
IMAGE: THE CAVE IN VIETNAM WHERE THE STALAGMITE WAS DISCOVEREDview more
CREDIT: ANNABEL WOLF
Scientists have discovered a new technique which will shed light on the phenomena of winter monsoons – the heavy autumn and winter rainfalls which can cause floods and landslides across southeast Asia.
While summer monsoons are well researched and understood, there is currently very limited understanding of winter monsoons – especially of how they have changed during periods when there has been no data available from weather stations.
It has therefore been difficult to make accurate, long-term predictions about the timing and intensity of winter rainfall in countries such as Vietnam, Thailand, Cambodia and Malaysia.
The Asian winter monsoon brings significant rainfall to some coastal areas of Vietnam, the Philippines, Southeast India, Sri Lanka and Japan, playing a critical role in agriculture and water resources, as well as natural hazard risks related to flooding and landslides.
These regions include some of the world’s largest food producers and exporters, causing not only the regional economy but also the already precarious global food trade to be vulnerable to changes in winter monsoon rainfall.
By examining an 8,000-year-old stalagmite from a cave in central Vietnam, researchers have been able to extract information about changes in seasonal rainfall patterns in Southeast Asia over thousands of years.
And, in a new research breakthrough, they have for the first time been able to distinguish between the rainfall caused by local weather conditions, and that which resulted from conditions across a much wider geographical area.
Annabel Wolf, now a postdoctoral scholar at the University of California, Irvine’s Department of Earth System Science, said: “The past evolution of the winter and summer monsoons in Southeast Asia has been debated for decades.
"By examining this stalagmite from Vietnam, we were able to track autumn and winter rainfall over a significant period and, crucially, to differentiate between the rain which had fallen due to local weather systems, and the rain caused by wider regional systems.
"Our main conclusion was that the regional component of the monsoon, caused by atmospheric circulation, shows a contradictory relationship between winter and summer monsoons, driven by insolation in the northern hemisphere.
"However, the results from the local rainfall samples showed a strong connection between summer and winter monsoons.”
The findings of the research mean there is now potential to re-examine samples from other areas in Southeast Asia and extract the local and regional rainfall levels, leading to much greater understanding of how weather patterns have evolved over time and how they may continue to change in future.
In contrast to the very well-studied Southwest Summer Monsoon, there are no robust records documenting the long-term changes in Southeast Asian rainfall associated with the Northeast Winter Monsoon under pre-industrial conditions. This means changes to rainfall in this region over longer timescales are not well understood.
As a result, many climate models underestimate the winter monsoon rainfall by as much as 50%, leaving considerable uncertainty in future climate projections.
Speaking about the research Dr Ersek said: “By shedding light on potential discrepancies in paleoclimate reconstructions, scientists now have a critical tool to refine their understanding of historical climate patterns.
"Our findings have the potential to inform policies and strategies aimed at mitigating the impacts of intense rainfall in Southeast Asia, which becomes more imperative as climate change continues to exert its influence on global weather patterns.”
IMAGE: WORD CLOUD OF ALL ARTICLES ANALYZED IN THIS REVIEWview more
CREDIT: YIHENG LIU
Recent advancements in natural language processing (NLP) have ushered in a new era with the emergence of powerful language models, most notably the Generative Pretrained Transformer (GPT) series, which includes substantial language models such as ChatGPT (GPT-3.5 and GPT-4). These models undergo extensive pre-training on vast textual data, and their capability is evident in their exceptional performance across a broad spectrum of NLP tasks, including language translation, text summarization, and question-answering. Notably, ChatGPT has demonstrated its potential across various domains, spanning education, healthcare, reasoning, text generation, human-machine interaction, and scientific research, to name just a few.
In line with this emerging and noteworthy trend, a team of researchers in China has undertaken a thorough analysis of research papers centered around ChatGPT. As of April 1st, 2023, a total of 194 papers referencing ChatGPT were identified on arXiv.
The team’s study encompassed a comprehensive trend analysis of these papers, resulting in the creation of a word cloud to visually depict the frequently used terminology. Additionally, they delved into the distribution of these papers across diverse fields, presenting statistical insights.
Moreover, their efforts extended to a comprehensive review of the existing literature on ChatGPT.
“Our review spans various dimensions, including an exploration of ChatGPT’s manifold applications, a thorough consideration of the ethical implications associated with its use, an evaluation of its capabilities, and an examination of its inherent limitations,” explains lead author Bao Ge.
The team’s findings indicate a rapid increase in interest in NLP models, showcasing their substantial potential across various domains.
"Nonetheless, it is essential to acknowledge the valid concerns surrounding biased or harmful content generation, privacy infringements and the potential for technology misuse,” Ge emphasizes. Mitigating these concerns and establishing a framework for the responsible and ethical development and deployment of ChatGPT stands as a paramount priority."
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Contact the author: Bao Ge. School of Physics and Information Technology, Shaanxi Normal University, Xi'an, 710119, Shaanxi, China. bob_ge@snnu.edu.cn
The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 100 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).
Summary of ChatGPT-Related research and perspective towards the future of large language models
COI STATEMENT
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
River sampling study shows impact of COVID-19 pandemic on London’s waterways
The most detailed study of a city’s waterways anywhere in the world has revealed how chemical pollutants in London’s rivers changed over the pandemic
IMAGE: WATER SAMPLING AT THE MILLENIUM BRIDGE, LONDONview more
CREDIT: MELANIE EGLI / IMPERIAL COLLEGE LONDON
The most detailed study of a city’s waterways anywhere in the world has revealed how chemical pollutants in London’s rivers changed over the pandemic.
In a study led by researchers at Imperial College London, scientists have shown how pollutants entering the capital’s river systems – including traces of prescription medications such as antibiotics and antidepressants – changed over the course of the COVID-19 pandemic.
The study, which involved hundreds of samples taken from 14 waterways in Greater London over three years,[1] focused particularly on how wastewater contaminates the city’s rivers and how this changed over the pandemic’s peak. The researchers believe their analysis, published in the journal Environment International, is by far the largest study globally tracking changes to contaminants in a major city’s river systems.[2]
It finds that during 2020 there was a significant decrease in traces of some types of pollutants, including pharmaceuticals, in the River Thames – the city’s main waterway. This coincided with national lockdowns and reduced numbers of people travelling or commuting into London. But levels of contaminants increased again significantly in 2021, with greater concentrations of antibiotics, anti-anxiety and anti-depressant medications entering the city’s waterways after restrictions were lifted.
The analysis also reveals that 21 of the compounds detected posed a potential risk to the environment in freshwater ecosystems, including antibiotics, pain medication and pet parasite medications. The researchers explain they were able to differentiate between pollutants and pinpoint their sources along waterways with a high level of geographical resolution, and that wastewater treatment plants and combined sewer overflows were the main sources of chemical risks overall. In addition, the team also detected a wide range of other chemicals including illicit drugs and neonicotinoid pesticides used in pet tick and flea medications.
They also found that smaller rivers feeding into the River Thames were most impacted by wastewater pollution, from both direct release from wastewater treatment plants and combined sewer overflows (CSOs). They add that the scale of wastewater monitoring used in their study could be used to gauge the direct and indirect impacts of changes in human activity, and the impact of wastewater processing, on the health of our rivers.
Dr Leon Barron, part of the Environmental Research Group at Imperial College London and senior author of the study, said: “This is the largest study of a heavily urbanised river system and provides us with uniquely detailed insights into several aspects of London’s water quality, most notably how the concentration of pharmaceuticals in our water changed over the course of the pandemic – reflecting changes in public health and reduced movement of people to, from and within London during lockdowns.”
Melanie Egli, PhD student and first author of the study, said: “This study enabled us to gain insights not only into what chemical contamination was in our rivers, but also provided us with high geographic resolution of where they are coming from. Crucially, we found that some small tributary rivers were particularly impacted by wastewater, highlighting the need for increased monitoring and infrastructure investment for their protection.”
Dr Barron added: “Aside from the pandemic, this work provides an important snapshot of chemical contamination before the Thames Tideway Tunnel ‘Super Sewer’ is opened in 2025, which aims to reduce pollution by over 95 %. This is a great start, but wastewater contamination in other rivers nationally needs urgent action.”
Professor Guy Woodward, Professor of Ecology in the Department of Life Sciences, and a co-author of the paper, commented: “This is a comprehensive and detailed study of the huge range of chemicals that we find in our freshwater ecosystems, and it picks up on several that are at potentially harmful concentrations for wildlife, but which have seemingly been overlooked in traditional surveys of our water quality in urban areas at this resolution.”
The research was supported by funding from the UKRI Medical Research Council (MRC) and the National Institute for Health and Care Research (NIHR). The study forms part of a project within the Environmental Research Group and the MRC Centre for Environment and Health at Imperial College London.
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NOTES TO EDITORS: This press release uses a labelling system developed by the Academy of Medical Sciences to improve the communication of evidence. For more information, please see: http://www.sciencemediacentre.org/wp-content/uploads/2018/01/AMS-press-release-labelling-system-GUIDANCE.pdf [1] River Thames, River Hogsmill, River Wandle, River Brent, River Crane, River Lee, River Lea, Channelsea River, Fray’s River, Grand Union Canal (Paddington Arm, Slough Arm), Pymmes Brook, and Beverley Brook [2] Over the course of three years, from 2019 to 2021, researchers collected and analysed almost 400 water samples from Greater London waterways. Overall, they found almost 100 pollutants of concern, with each pollutant detected at least once. Analysis revealed how these compounds changed over the course of the COVID-19 pandemic. Collection took place in the last three months of each year for consistency, and samples were taken by Melanie Egli, PhD student within the Environmental Research Group and the MRC Centre for Environment and Health at Imperial. Using the 2019 data as a baseline, the team was able to detect statistical changes in the concentration of compounds. Analysis revealed the presence of three compounds classed as high-risk contaminants – posing a risk to the environment or increased antimicrobial resistance. These include imidacloprid (a parasiticide found principally in flea medications for domestic pets), azithromycin (an antibiotic), and diclofenac (an anti-inflammatory). The largest risk compound was imidacloprid, aligning with previous findings on the environmental impact of pet parasiticides. In addition, the study found that despite an initial dip in compounds in 2020, by 2021, levels of many pharmaceutical compounds and metabolites had exceeded pre-pandemic levels (measured against the 20129 baseline). The findings match prescribing data trends, which show a year-on-year increase in the prescription of antidepressants and anti-anxiety medications in England. They also show the smaller rivers feeding into the Thames were the most impacted by wastewater pollution, released directly from wastewater treatment plants and combined sewage overflows (CSOs), with the city’s eight plants believed to be operating at 96% of their population capacity, and higher than the UK average (88%). Four rivers were most impacted by outputs from treatment plants and CSOs: the River Lea, Beverley Brook, River Wandle, and the Hogsmill River, all of which feed into the River Thames.
IMAGE: (A) AMONG THE ADHERING SPECIES, THE ROCK-CLIMBING FISH CAN GENERATE GREAT ADHESION FORCE WITH AMAZING CRAWLING ABILITY UNDERWATER. (B) THE SETAE ARRAY ON THE BROWN SHADED AREA CONFORMS TO THE SUBSTRATE AND FORMS A SEALING CHAMBER THROUGH THE STEFAN FORCE; THE INNER CAVITY OF THE SUCTION CUP IN THE BLUE AREA PRESENTS A PRESSURE CHANGE DUE TO THE VOLUME CHANGE WHEN THE PULL-OFF FORCE IS IMPOSED. (C) THE MECHANISM FOR GENERATING THE NEGATIVE PRESSURE ADHESION: UPON THE ACTION OF THE PULL-OFF FORCE, THE MICRO SETAE AT THE EDGE OF THE SUCTION CUP ARE KEPT IN CONTACT WITH THE SUBSTRATE BY FORCE “FA-SETAE” DUE TO THE HYDRODYNAMIC INTERACTIONS, AND THE SUCTION CUP KEEPS SEALED DURING THE PULL-OFF PROCESS. HOWEVER, THE SUCTION CUP DEFORMS TO INCREASE ITS VOLUME AND DECREASE ITS INNER PRESSURE TO GENERATE NEGATIVE PRESSURE ADHESION TO RESIST THE PULL-OFF FORCE THROUGHOUT THE PROCESS. (D) A BIONIC CRAWLING FISH NAMED CLIMBOT, AN UNDERWATER CLIMBING ROBOT WAS DESIGNED BASED ON THE ADHESION MECHANISM OF THE FISH, WHICH CAN CRAWL AT A MAXIMUM SPEED OF 3.7 BL/S AND HAS AN ADHESION FORCE OF 25.67 ± 2.81 N.view more
Underwater "traffic" encompasses a fascinating variety of creatures, from fish with their graceful swimming postures to jet-propelled jellyfish and remoras hitching rides on other organisms. Among these, a remarkable species known as the "underwater gecko", the rock-climbing fish(Beaufortia kweichowensis), stands out. This extraordinary creature possesses a unique set of abilities – it can swiftly slide along underwater surfaces like an ice skater, crawl against water currents, and securely adhere to a fixed position with remarkable adhesion force.
Recently, a collaborative effort between the research team led by Prof. Lianqing Liu at the Shenyang Institute of Automation, Chinese Academy of Sciences, and institutions including the Chengdu Institute of Biology, Chinese Medical University, Tsinghua University, and the University of Hong Kong, has shed light on the closely guarded secrets behind the rock-climbing fish’s dynamic adhesion and rapid crawling movements. The team has also designed an underwater biomimetic adhering-sliding robot inspired by the rock-climbing fish. This innovative robot can achieve tight adhesion on a moving ship model and slide smoothly underwater.
The research team highlighted that the Climbot's impressive adhesion ability enables it to cling with a force equivalent to 1000 times its weight while accomplishing a remarkable glide at a speed of 7.83 times its body length per second. The mechanism underlying this unique dynamic adaptive adhesion capability has long remained an enigma, intriguing researchers in the field of underwater robotics. Balancing substantial surface adhesion with agile and swift gliding poses a significant challenge, as increased adhesion often results in heightened surface contact stress.
Prof. Liu said “Typically, reversible underwater adhesion relies on a negative pressure adhesion mechanism, a system adopted by rock-climbing fish as well. However, the mystery lies in the fact that other creatures such as remoras and octopuses, also utilizing negative pressure adhesion, cannot execute surface gliding like the rock-climbing fish.”
The secret to the rock-climbing fish's exceptional adhesion-gliding prowess lies in the setae structures present on the edges of its suction cups. These setae, measuring 4-6 micrometers in diameter and 12-14 micrometers in length, convert the contact area with water into a "sticky" gel-like substance under the influence of Stefan force, firmly attaching the suction cups to the surface and creating a dynamic water seal. This unique suction cup can passively deform its soft abdomen to counteract external detachment forces, or actively contract its abdomen to generate a powerful adhesion force, anchoring itself securely to a particular position. Moreover, the water film present at the contact interface acts as a "lubrication film" during movement, reducing frictional resistance and facilitating smooth surface gliding. This ingenious mechanism effectively balances the conflict between substantial adhesion and rapid sliding.
Drawing inspiration from this discovery, the research team successfully utilized micro-nano lithography and molding techniques to fabricate setae arrays, integrating them into 3D-printed soft suction cups, and incorporating a control unit to design and create the Climbot, an underwater adhering-sliding robot. The Climbot can tightly adhere to the surface of a moving ship model and glide effortlessly underwater.
This groundbreaking research showcases a novel underwater locomotion, and the potential applications of "Climbot" underwater suction-crawling robot technology hold promising prospects in the fields of marine science, underwater exploration, and ocean engineering.
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This work has been published at National Science Review. See the article:
Uncover rock-climbing fish’s secret of balancing tight adhesion and fast sliding for bioinspired robots
