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Showing posts sorted by date for query ROBOT. Sort by relevance Show all posts

Sunday, October 04, 2026

 

No battery needed: Robot skin harvests power as it walks







Science China Press
No Battery Needed: Robot Skin Harvests Power as It Walks

image: 

Engineered electrochemical polymer skin membrane enables continuous operation and intelligence in microrobots.

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Credit: ©Science China Press




Powering microrobots has long been a chemical engineering problem. A 1.7 g microrobot can crawl for only about two minutes on commercial batteries. To run for two hours, it would need a battery weighing 94% of its total mass, with an energy density of 5382 Wh kg−1, far beyond today’s lithium-ion technology. Below 1 cm3 or 1 g, microbatteries lose energy density even faster because packaging and conductive materials take up a growing share of their mass.

From carrying batteries to walking on energy

A team led by Yue Gao at Fudan University’s Department of Macromolecular Science tried a different route. Instead of making batteries smaller and denser, the researchers asked whether the robot could harvest energy from the surface it walks on. Active materials such as aluminum, zinc, silicon, tin, and lead are common in pipes, buildings, data centers, and equipment. If a robot’s foot could trigger a chemical reaction on contact, its runtime would no longer be limited by onboard storage.

The team’s answer is an open electrochemical power system: a crosslinked potassium polyacrylate membrane attached to the microrobot’s foot. It converts chemical energy from the substrate and from atmospheric moisture and oxygen into electricity.

A skin that powers, grips, and senses

The membrane is made in one step by polymerizing acrylic acid monomer, crosslinker, initiator, and potassium hydroxide directly on the robot’s foot. A flexible platinum/carbon film acts as the reaction site for oxygen and water. The skin can be as thin as 135 micrometers and as small as 1 square millimeter. On zinc, it delivers a power density of 133 mW cm−2; on aluminum, 103 mW cm−2. These values are about an order of magnitude higher than those of typical microbatteries. The system also retains its current capability when scaled down to 0.0004 cm3. The design must satisfy several conflicting needs at once. It has to hold water, stay flexible, stick to surfaces, release easily, and sense the ground.

Holding water and surviving extreme temperatures

The membrane’s carboxylate groups, potassium ions, and hydroxide ions interact strongly with water molecules. Even at 20% relative humidity, similar to the Sahara Desert, it retains most of its water and continues to discharge after 48 hours. At −20°C, potassium ions disrupt the ordered hydrogen-bond network of water, keeping the membrane ionically conductive. The voltage drops by only about 0.2 V compared with room temperature. The crosslinked structure also allows operation at 80°C. After water evaporates, adding water restores performance.

Power on contact, off on lift-off

The membrane generates electricity when it touches an active substrate and stops when the foot lifts. The substrate loses electrons. On the platinum/carbon side, oxygen and water accept electrons to produce hydroxide ions. The reaction starts in about 0.1 milliseconds and stops when contact ends. Each walking step refreshes the reaction interface. Discharge products remain on the substrate rather than accumulating on the membrane, avoiding the performance decay seen in static batteries.

Sticky in the right direction

The membrane combines strong shear adhesion with easy normal detachment. Carboxylate groups create electrostatic adhesion to metal substrates. In the walking direction, adhesion is strong enough to prevent slipping. In the vertical direction, detachment resistance is low, so the robot can lift its foot efficiently. This allows the microrobot to crawl on inclined aluminum surfaces.

Sensing the ground through ions

The membrane can also sense the surface beneath it. Different materials cause different electrochemical reaction rates and hydroxide consumption, leading to directed migration of potassium ions and a characteristic potential signal. Rough surfaces deform the membrane and change ion distribution, producing another signal. Material changes generate stable square-wave signals, while roughness changes produce millivolt-level spikes. The two signals can be naturally decoupled. With an X-Y electrode array, the membrane can also locate where contact occurs. This helps the robot recognize its environment and actively seek energy-rich paths.

No Battery Needed: Robot Skin Harvests Power as It Walks

Electrochemical performance of the skin membrane.

Credit

©Science China Press

 

 

Require satellite evidence for energy and AI data center approvals, researchers urge governments




University of Surrey





Satellite data could help governments decide where to build the data centres behind the growth of AI, by showing where renewable power, water and land are available and where drought and climate risks are highest, according to researchers at the University of Surrey. 

Writing in Nature Reviews Clean Technology, the team argues that Earth observation (information about the planet's systems gathered largely by satellites), which is often underused, should become a formal part of how governments, regulators and investors plan, run and check the clean energy transition. 

The call from Surrey researchers comes as demand floods the queue to connect to Britain's electricity grid. According to Ofgem, contracted demand in that queue rose from 41 gigawatts to 125 gigawatts between November 2024 and June 2025, driven largely by data centre projects. 

Globally, the International Energy Agency expects electricity use by data centres to double from 485 terawatt-hours in 2025 to 950 terawatt-hours by 2030, roughly the amount of electricity Japan uses in a year. 

The authors say geospatial and satellite data can support more strategic data centre planning by combining information on renewable energy potential, land-surface temperature, open water and groundwater availability, drought exposure, biodiversity, land-use constraints and climate-risk projections.  

Dr Ana Andries, Senior Lecturer in GIS, Remote Sensing and Environmental Assessment and lead author of the Comment from the University of Surrey, said: 

  

"Every new data centre is a long-term decision about power, water and land, while also an increasing source of global carbon emissions. Satellites already give us detailed and regularly updated information on all three, yet that evidence is too often left out of the decisions that matter. We're asking governments to write it into the rules, so the infrastructure behind the AI boom goes where the grid, renewable energy potential and the landscape can support it." 

The Comment also sets out how satellites and related geospatial data support planning, operation and monitoring. For planning, the Global Solar Atlas uses satellite data to map solar power potential worldwide, while MapYourGrid, an open-source community project, is mapping power lines, substations and power plants so planners can see where new generation can connect. Once infrastructure is running, thermal imaging from space could help identify faults such as hot spots on solar panels, while radar from Sentinel-1 satellites can map wind at the sea surface around offshore wind farms, including the slower air in the wakes the farms leave behind. 

Water is one area where energy systems are exposed. For instance, this summer's drought pushed the Danube to record lows and forced Romania to shut down both reactors at the Cernavodă nuclear plant, which normally supplies about a fifth of the country's electricity. Climate data and satellite monitoring of river levels, reservoirs and drought can help estimate risks to hydropower and to power stations that rely on river water for cooling, and help protect a dispatchable electricity supply. For accountability, some methane-sensing satellites detected releases as small as 0.03 tonnes per hour in single-blind controlled tests, though performance varied between systems. This gives regulators a way to check emissions from oil and gas infrastructure. Satellite imagery has also been used to map mining expansion linked to clean-energy supply chains in the Democratic Republic of Congo. 

The authors call on governments and regulators to require satellite evidence in renewable energy zoning, infrastructure permitting, climate-risk screening and environmental impact assessment, especially where projects affect land, water, biodiversity or grid access. Energy plans and regulatory reporting should also set out clear data standards, validation requirements and how uncertainty is reported. For investors and utilities, they argue, satellite data should become part of due diligence and asset-risk assessment. Satellite data should support these decisions, they add, not replace ground data, local knowledge or official reporting. 

Delivering this will need capacity building, the authors say – energy ministries, regulators, utilities, local authorities and investors need trusted satellite products, practical guidance, standards, training and evidence that the approach is cost-effective. 

Professor Ravi Silva, Distinguished Professor and Director of the Advanced Technology Institute at the University of Surrey and co-author of the Comment, said: 

"Building a clean energy future requires thousands of decisions, from choosing locations for solar farms, wind turbines, transmission infrastructure and energy storage to ensuring these assets operate effectively over their lifetime. Better evidence helps make these decisions more efficient, cost-effective and reliable. Satellite data can help identify areas with strong solar and wind resources, map existing infrastructure, detect operational issues, and provide independent information to support monitoring and oversight." 

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Notes to editors 

  • Citation: Andries, A., Xuan, J., Liu, L. et al. Leverage Earth observation data to support the clean energy transition. Nat. Rev. Clean Technol. (2026). https://doi.org/10.1038/s44359-026-00220-y 


Learning maths goes (slightly) better with AI, but teacher plays a key role



Primary school pupils who use an AI-supported learning tool learn arithmetic more quickly than children who do not use such a tool



Radboud University Nijmegen





Primary school pupils who use an AI-supported learning tool learn arithmetic more quickly than children who do not use such a tool. This is the finding of a multi-year study by Radboud University involving nearly eight thousand children. However, the researchers warn that it's no miracle cure, as the teacher’s role remains essential even with AI.

The researchers examined the development of numeracy skills among 7,885 Dutch primary school pupils over a three-year period, when these systems were first used between 2014 and 2017. They compared classes that used an adaptive learning system with classes that taught numeracy without such a system. Such a system automatically adapts exercises to the level of an individual pupil. Pupils are given more difficult tasks if they perform well and simpler tasks if they get stuck. On average, pupils who used the system showed more positive growth in their maths performance over the years.

Large-scale study

‘It is one of the first studies to examine the long-term effects of adaptive learning tools. Until now, research into these kinds of systems has mainly focused on short-term effects, or has been conducted on a smaller scale,’ explains Susanne de Mooij, an education researcher and one of the study’s authors.

‘Adaptive learning systems have been in use for almost fifteen years in more than half of all Dutch primary schools. Nevertheless, some fear that this type of adaptive learning tool leads to pupils learning less effectively, as digital learning materials are thought to be less effective than paper-based ones. This study shows that, in cognitive terms at least, this is not the case.’

Greater success at large schools

The effects found are modest, De Mooij emphasises. ‘We have found small effects, but generally a positive trend. Moreover, the positive effect is particularly evident in large schools and in vulnerable schools with many pupils from less advantaged socio-economic backgrounds. There is often greater variation between pupils in such settings. Adaptive technology can then help to better tailor teaching to individual needs,’ says De Mooij.

This means that an adaptive learning tool is primarily something that supports teachers, rather than replacing them. ‘A teacher cannot adapt the lesson content to thirty pupils at the same time. But with a tool like this, you can improve pupils’ maths skills whilst also reducing a teacher’s workload.’ The researchers emphasise that the teacher always remains in control: ‘The teacher draws up the lesson plan, decides what pupils learn and oversees what happens in the classroom. Such learning technology is fed solely by the data stored in the system, whereas a teacher has access to much more information.’