探花直播 of Cambridge - 3D printing

Using lasers to ‘heat and beat’ 3D-printed steel could help reduce costs

sc604 — Mon, 30 Oct 2023 09:01:39 +0000

探花直播method, developed by a research team led by the 探花直播 of Cambridge, allows structural modifications to be ‘programmed’ into metal alloys during 3D printing, fine-tuning their properties without the ‘heating and beating’ process that’s been in use for thousands of years.

探花直播new 3D printing method combines the best qualities of both worlds: the complex shapes that 3D printing makes possible, and the ability to engineer the structure and properties of metals that traditional methods allow. 探花直播results are reported in the journal Nature Communications.

3D printing has several advantages over other manufacturing methods. For example, it’s far easier to produce intricate shapes using 3D printing, and it uses far less material than traditional metal manufacturing methods, making it a more efficient process. However, it also has significant drawbacks.

“There’s a lot of promise around 3D printing, but it’s still not in wide use in industry, mostly because of high production costs,” said Dr Matteo Seita from Cambridge’s Department of Engineering, who led the research. “One of the main drivers of these costs is the amount of tweaking that materials need after production.”

Since the Bronze Age, metal parts have been made through a process of heating and beating. This approach, where the material is hardened with a hammer and softened by fire, allows the maker to form the metal into the desired shape and at the same time impart physical properties such as flexibility or strength.

“ 探花直播reason why heating and beating is so effective is because it changes the internal structure of the material, allowing control over its properties,” said Seita. “That’s why it’s still in use after thousands of years.”

One of the major downsides of current 3D printing techniques is an inability to control the internal structure in the same way, which is why so much post-production alteration is required. “We’re trying to come up with ways to restore some of that structural engineering capability without the need for heating and beating, which would in turn help reduce costs,” said Seita. “If you can control the properties you want in metals, you can leverage the greener aspects of 3D printing.”

Working with colleagues in Singapore, Switzerland, Finland and Australia, Seita developed a new ‘recipe’ for 3D-printed metal that allows a high degree of control over the internal structure of the material as it is being melted by a laser.

By controlling the way that the material solidifies after melting, and the amount of heat that is generated during the process, the researchers can programme the properties of the end material. Normally, metals are designed to be strong and tough, so that they are safe to use in structural applications. 3D-printed metals are inherently strong, but also brittle.

探花直播strategy the researchers developed gives full control over both strength and toughness, by triggering a controlled reconfiguration of the microstructure when the 3D-printed metal part is placed in a furnace at relatively low temperature. Their method uses conventional laser-based 3D printing technologies, but with a small tweak to the process.

“We found that the laser can be used as a ‘microscopic hammer’ to harden the metal during 3D printing,” said Seita. “However, melting the metal a second time with the same laser relaxes the metal’s structure, allowing the structural reconfiguration to take place when the part is placed in the furnace.”

Their 3D printed steel, which was designed theoretically and validated experimentally, was made with alternating regions of strong and tough material, making its performance comparable to steel that’s been made through heating and beating.

“We think this method could help reduce the costs of metal 3D printing, which could in turn improve the sustainability of the metal manufacturing industry,” said Seita. “In the near future, we also hope to be able to bypass the low-temperature treatment in the furnace, further reducing the number of steps required before using 3D printed parts in engineering applications.”

探花直播team included researchers from Nanyang Technological 探花直播, the Agency for Science, Technology and Research (A*STAR), the Paul Scherrer Institute, VTT Technical Research Centre of Finland, and the Australian Nuclear Science & Technology Organisation. Matteo Seita is a Fellow of St John’s College, Cambridge.

Reference:
Shubo Gao et al. ‘Additive manufacturing of alloys with programmable microstructure and properties.’ Nature Communications (2023). DOI: 10.1038/s41467-023-42326-y

Researchers have developed a new method for 3D printing metal that could help reduce costs and make more efficient use of resources.

This method could help reduce the costs of metal 3D printing, which could in turn improve the sustainability of the metal manufacturing industry

Matteo Seita

Jude E. Fronda

Retrieval of a stainless steel part made by 3D printing

探花直播text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright ? 探花直播 of Cambridge and licensors/contributors as identified.? All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

Cambridge researchers help develop smart, 3D printed concrete wall for National Highways project

sc604 — Thu, 13 Jul 2023 12:01:02 +0000

探花直播3D-printed structure – a type of retaining wall known as a headwall – has been installed on the A30 in Cornwall, where it is providing real-time information thanks to Cambridge-designed sensors embedded in its structure. 探花直播sensors provide up-to-date measurements including temperature, strain and pressure. This ‘digital twin’ of the wall could help spot and correct faults before they occur.

Headwall structures are normally made in limited shapes from precast concrete, requiring formwork and extensive steel reinforcement. But by using 3D printing, the team – including specialists from Costain, Jacobs and Versarien – could design and construct a curved hollow wall with no formwork and no steel reinforcement. 探花直播wall gets its strength not from steel, but from geometry instead.

探花直播wall – which took one hour to print – is roughly two metres high and three and a half metres across. It was printed in Gloucestershire at the headquarters of the advanced engineering company Versarien, using a robot arm-based concrete printer. Making the wall using 3D printing significantly saves on costs, materials and carbon emissions.

Over the past six years, Professor Abir Al-Tabbaa’s team in the Department of Engineering has been developing new sensor technologies and exploring the effectiveness of existing commercial sensors to get better-quality information out of infrastructure. Her team has also developed various ‘smart’ self-healing concretes. For this project, they supplied sensors to measure temperature during the printing process.

Temperature variations at different layers of the 3D-printed wall were continuously monitored to detect any potential hotspots, thermal gradients, or anomalies. 探花直播temperature data will be correlated with the corresponding thermal imaging profile to understand the thermal behaviour of the 3D-printed wall.

“Since you need an extremely fast-setting cement for 3D printing, it also generates an enormous amount of heat,” said Al-Tabbaa. “We embedded our sensors in the wall to measure temperature during construction, and now we’re getting data from them while the wall is on site.” ?

In addition to temperature, the sensors measure relative humidity, pressure, strain, electrical resistivity, and electrochemical potential. 探花直播measurements provide valuable insights into the reliability, robustness, accuracy, and longevity of the sensors.

A LiDAR system also was used to scan the wall as it was being printed to create a 3D point cloud and generate a digital twin of the wall.

“Making the wall digital means it can speak for itself,” said Al-Tabbaa. “And we can use our sensors to understand these 3D printed structures better and accelerate their acceptance in industry.”

探花直播Cambridge team developed a type of sensor, known as a PZT (Piezoceramic Lead-Zirconate-Titanate) sensor, which measures electromechanical impedance response and monitors changes in these measurements over time to detect any possible damage. These smart sensors can show how 3D-printed mortar hardens over time, while simultaneously monitoring the host structure’s health.

Eight PZT sensors were embedded within the wall layers at different positions during the 3D printing process to capture the presence of loading and strain, both during the construction process and service life after field installation.

探花直播team, which included experts in smart materials, automation and robotics and data science, also developed a bespoke wireless data acquisition system. This enabled the collection of the multifrequency electromechanical response data of the embedded sensors remotely from Cambridge.

“This project will serve as a living laboratory, generating valuable data over its lifespan,” said Al-Tabbaa. “ 探花直播sensor data and ‘digital twin’ will help infrastructure professionals better understand how 3D printing can be used and tailored to print larger and more complex cement-based materials for the strategic road network.”

Members of the team included Dr Sripriya Rengaraju, Dr Christos Vlachakis, Dr Yen-Fang Su, Dr Damian Palin, Dr Hussam Taha, Dr Richard Anvo and Dr Lilia Potseluyko from Cambridge; as well as Costain’s Head of Materials Bhavika Ramrakhyani, a part-time PhD student in the Department of Engineering, and Ben Harries, Architectural Innovation Lead at Versarien, who is also starting a part-time PhD in the Department of Engineering in October.

探花直播Cambridge team’s work is part of the Resilient Materials for Life Programme and the Digital Roads of the Future Initiative. 探花直播research is supported in part by the Engineering and Physical Sciences Research Council (EPSRC), part of UK Research and Innovation (UKRI), and the European Union.

Cambridge researchers, working in partnership with industry, have helped develop the first 3D-printed piece of concrete infrastructure to be used on a National Highways project.

Making the wall digital means it can speak for itself, and we can use our sensors to understand these 3D-printed structures better and accelerate their acceptance in industry

Abir Al-Tabbaa

Cool Concrete – the smart, 3D printed concrete wall used for National Highways project.

National Highways

3D printed retaining wall

Yes

Algorithm learns to correct 3D printing errors for different parts, materials and systems

sc604 — Tue, 16 Aug 2022 15:11:40 +0000

探花直播engineers, from the 探花直播 of Cambridge, developed a machine learning algorithm that can detect and correct a wide variety of different errors in real time, and can be easily added to new or existing machines to enhance their capabilities. 3D printers using the algorithm could also learn how to print new materials by themselves. Details of their low-cost approach are reported in the journal Nature Communications.

3D printing has the potential to revolutionise the production of complex and customised parts, such as aircraft components, personalised medical implants, or even intricate sweets, and could also transform?manufacturing supply chains. However, it is also vulnerable to production errors, from small-scale inaccuracies and mechanical weaknesses through to total build failures.

Currently, the way to prevent or correct these errors is for a skilled worker to observe the process. 探花直播worker must recognise an error (a challenge even for the trained eye), stop the print, remove the part, and adjust settings for a new part. If a new material or printer is used, the process takes more time as the worker learns the new setup. Even then, errors may be missed as workers cannot continuously observe multiple printers at the same time, especially for long prints.

“3D printing is challenging because there's a lot that can go wrong, and so quite often 3D prints will fail,” said Dr Sebastian Pattinson from Cambridge’s Department of Engineering, the paper’s senior author. “When that happens, all of the material and time and energy that you used is lost.”

Engineers have been developing automated 3D printing monitoring, but existing systems can only detect a limited range of errors in one part, one material and one printing system.

“What’s really needed is a ‘driverless car’ system for 3D printing,” said first author Douglas Brion, also from the Department of Engineering. “A driverless car would be useless if it only worked on one road or in one town – it needs to learn to generalise across different environments, cities, and even countries. Similarly, a ‘driverless’ printer must work for multiple parts, materials, and printing conditions.”

Brion and Pattinson say the algorithm they’ve developed could be the ‘driverless car’ engineers have been looking for.

“What this means is that you could have an algorithm that can look at all of the different printers that you're operating, constantly monitoring and making changes as needed – basically doing what a human can't do,” said Pattinson.

探花直播researchers trained a deep learning computer vision model by showing it around 950,000 images captured automatically during the production of 192 printed objects. Each of the images was labelled with the printer’s settings, such as the speed and temperature of the printing nozzle and flow rate of the printing material. 探花直播model also received information about how far those settings were from good values, allowing the algorithm to learn how errors arise.

“Once trained, the algorithm can figure out just by looking at an image which setting is correct and which is wrong – is a particular setting too high or too low, for example, and then apply the appropriate correction,” said Pattinson. “And the cool thing is that printers that use this approach could be continuously gathering data, so the algorithm could be continually improving as well.”

Using this approach, Brion and Pattinson were able to make an algorithm that is generalisable – in other words, it can be applied to identify and correct errors in unfamiliar objects or materials, or even in new printing systems.

“When you’re printing with a nozzle, then no matter the material you’re using – polymers, concrete, ketchup, or whatever – you can get similar errors,” said Brion. “For example, if the nozzle is moving too fast, you often end up with blobs of material, or if you’re pushing out too much material, then the printed lines will overlap forming creases.

“Errors that arise from similar settings will have similar features, no matter what part is being printed or what material is being used. Because our algorithm learned general features shared across different materials, it could say ‘Oh, the printed lines are forming creases, therefore we are likely pushing out too much material’.”

As a result, the algorithm that was trained using only one kind of material and printing system was able to detect and correct errors in different materials, from engineering polymers to even ketchup and mayonnaise, on a different kind of printing system.

In future, the trained algorithm could be more efficient and reliable than a human operator at spotting errors. This could be important for quality control in applications where component failure could have serious consequences.

With the support of Cambridge Enterprise, the 探花直播’s commercialisation arm, Brion has formed Matta, a spin-out company that will develop the technology for commercial applications.

“We’re turning our attention to how this might work in high-value industries such as the aerospace, energy, and automotive sectors, where 3D printing technologies are used to manufacture high-performance and expensive parts,” said Brion. “It might take days or weeks to complete a single component at a cost of thousands of pounds. An error that occurs at the start might not be detected until the part is completed and inspected. Our approach would spot the error in real time, significantly improving manufacturing productivity.”

探花直播research was supported by the Engineering and Physical Sciences Research Council, Royal Society, Academy of Medical Sciences, and the Isaac Newton Trust.

探花直播full dataset used to train the AI is freely available online.?

Reference:
Douglas A J Brion & Sebastian W Pattinson. ‘Generalisable 3D printing error detection and correction via multi-head neural networks.’ Nature Communications (2022). DOI: 10.1038/s41467-022-31985-y

Engineers have created intelligent 3D printers that can quickly detect and correct errors, even in previously unseen designs, or unfamiliar materials like ketchup and mayonnaise, by learning from the experiences of other machines.

Once trained, the algorithm can figure out just by looking at an image which setting is correct and which is wrong

Sebastian Pattinson

Douglas Brion

Example image of the 3D printer nozzle used by the machine learning algorithm to detect and correct errors in real time.

探花直播text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright ? 探花直播 of Cambridge and licensors/contributors as identified.? All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

3D-printed ‘invisible’ fibres can sense breath, sound, and biological cells

sc604 — Wed, 30 Sep 2020 18:00:00 +0000

Researchers from the 探花直播 of Cambridge used 3D printing, also known as additive manufacturing, techniques to make electronic fibres, each 100 times thinner than a human hair, creating sensors beyond the capabilities of conventional film-based devices.

探花直播fibre printing technique, reported in the journal Science Advances, can be used to make non-contact, wearable, portable respiratory sensors. These printed sensors are high-sensitivity, low-cost and can be attached to a mobile phone to collect breath pattern information, sound and images at the same time.

First author Andy Wang, a PhD student from Cambridge’s Department of Engineering, used the fibre sensor to test the amount of breath moisture leaked through his face covering, for respiratory conditions such as normal breathing, rapid breathing, and simulated coughing. 探花直播fibre sensors significantly outperformed comparable commercial sensors, especially in monitoring rapid breathing, which replicates shortness of breath.

While the fibre sensor has not been designed to detect viral particles, since scientific evidence increasingly points to the fact that viral particles such as coronavirus can be transmitted through respiratory droplets and aerosols, measuring the amount and direction of breath moisture that leaks through different types of face coverings could act an indicator in the protection ‘weak’ points. ?

探花直播team found that most leakage from fabric or surgical masks comes from the front, especially during coughing, while most leakage from N95 masks comes from the top and sides with tight fittings. Nonetheless, both types of face masks, when worn properly, help to weaken the flow of exhaled breath.

“Sensors made from small conducting fibres are especially useful for volumetric sensing of fluid and gas in 3D, compared to conventional thin-film techniques, but so far, it has been challenging to print and incorporate them into devices, and to manufacture them at scale,” said Dr Yan Yan Shery Huang from Cambridge’s Department of Engineering, who led the research.

Huang and her colleagues 3D printed the composite fibres, which are made from silver and/or semiconducting polymers. This fibre printing technique creates a core-shell fibre structure, with a high-purity conducting fibre core wrapped by a thin protective polymer sheath, similar to the structure of common electrical wires, but at a scale of a few micrometres in diameter.

In addition to the respiratory sensors, the printing technique can also be used to make biocompatible fibres of a similar dimension to biological cells, which enables them to guide cell movements and ‘feel’ this dynamic process as electrical signals. Also, the fibres are so tiny that they are invisible to the naked eye, so when they are used to connect small electronic elements in 3D, it would seem that the electronics are ‘floating’ in mid-air.

“Our fibre sensors are lightweight, cheap, small and easy to use, so they could potentially be turned into home-test devices to allow the general public to perform self-administered tests to get information about their environments,” said Huang.

探花直播team looks to develop this fibre-printing technique for a number of multi-functional sensors, which could potentially detect more breath species for mobile health monitoring, or for bio-machine interface applications.

Reference:
Wenyu Wang et al. ‘Inflight fiber printing toward array and 3D optoelectronic and sensing architectures.’ Science Advances (2020). DOI: 10.1126/sciadv.aba0931

From capturing your breath to guiding biological cell movements, 3D printing of tiny, transparent conducting fibres could be used to make devices which can ‘smell, hear and touch’ – making it particularly useful for health monitoring, Internet of Things and biosensing applications.

Our fibre sensors are lightweight, cheap, small and easy to use, so they could potentially be turned into home-test devices to allow the general public to perform self-administered tests to get information about their environments

Yan Yan Shery Huang

Andy Wang

Fibre sensor attached to a face covering detects human breath with high sensitivity and responsiveness

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探花直播Facebook post that launched a thousand shields (and counting)

lw355 — Thu, 03 Sep 2020 07:30:53 +0000

Cambridge researchers are?supporting a project to 3D-print face shields and face masks in Malawi. 探花直播work?is helping?them create a 'blueprint' for using digital fabrication technologies in future emergencies.