̽��ֱ�� of Cambridge - Yan Yan Shery Huang

Imperceptible sensors made from ��electronic spider silk�� can be printed directly on human skin

sc604 — Fri, 24 May 2024 09:23:44 +0000

̽��ֱ��method, developed by researchers from the ̽��ֱ�� of Cambridge, takes its inspiration from spider silk, which can conform and stick to a range of surfaces. These ��spider silks�� also incorporate bioelectronics, so that different sensing capabilities can be added to the ��web��.

̽��ֱ��fibres, at least 50 times smaller than a human hair, are so lightweight that the researchers printed them directly onto the fluffy seedhead of a dandelion without collapsing its structure. When printed on human skin, the fibre sensors conform to the skin and expose the sweat pores, so the wearer doesn��t detect their presence. Tests of the fibres printed onto a human finger suggest they could be used as continuous health monitors.

This low-waste and low-emission method for augmenting living structures could be used in a range of fields, from healthcare and virtual reality, to electronic textiles and environmental monitoring. ̽��ֱ��results are reported in the journal Nature Electronics.

Although human skin is remarkably sensitive, augmenting it with electronic sensors could fundamentally change how we interact with the world around us. For example, sensors printed directly onto the skin could be used for continuous health monitoring, for understanding skin sensations, or could improve the sensation of ��reality�� in gaming or virtual reality application.

While wearable technologies with embedded sensors, such as smartwatches, are widely available, these devices can be uncomfortable, obtrusive and can inhibit the skin��s intrinsic sensations.

��If you want to accurately sense anything on a biological surface like skin or a leaf, the interface between the device and the surface is vital,�� said Professor Yan Yan Shery Huang from Cambridge��s Department of Engineering, who led the research. ��We also want bioelectronics that are completely imperceptible to the user, so they don��t in any way interfere with how the user interacts with the world, and we want them to be sustainable and low waste.��

There are multiple methods for making wearable sensors, but these all have drawbacks. Flexible electronics, for example, are normally printed on plastic films that don��t allow gas or moisture to pass through, so it would be like wrapping your skin in cling film. Other researchers have recently developed flexible electronics that are gas-permeable, like artificial skins, but these still interfere with normal sensation, and rely on energy- and waste-intensive manufacturing techniques.

3D printing is another potential route for bioelectronics since it is less wasteful than other production methods, but leads to thicker devices that can interfere with normal behaviour. Spinning electronic fibres results in devices that are imperceptible to the user, but don't have a high degree of sensitivity or sophistication, and they��re difficult to transfer onto the object in question.

Now, the Cambridge-led team has developed a new way of making high-performance bioelectronics that can be customised to a wide range of biological surfaces, from a fingertip to the fluffy seedhead of a dandelion, by printing them directly onto that surface. Their technique takes its inspiration in part from spiders, who create sophisticated and strong web structures adapted to their environment, using minimal material.

̽��ֱ��researchers spun their bioelectronic ��spider silk�� from PEDOT:PSS (a biocompatible conducting polymer), hyaluronic acid and polyethylene oxide. ̽��ֱ��high-performance fibres were produced from water-based solution at room temperature, which enabled the researchers to control the ��spinnability�� of the fibres. ̽��ֱ��researchers then designed an orbital spinning approach to allow the fibres to morph to living surfaces, even down to microstructures such as fingerprints.

Tests of the bioelectronic fibres, on surfaces including human fingers and dandelion seedheads, showed that they provided high-quality sensor performance while being imperceptible to the host.

��Our spinning approach allows the bioelectronic fibres to follow the anatomy of different shapes, at both the micro and macro scale, without the need for any image recognition,�� said Andy Wang, the first author of the paper. ��It opens up a whole different angle in terms of how sustainable electronics and sensors can be made. It��s a much easier way to produce large area sensors.��

Most high-resolution sensors are made in an industrial cleanroom and require the use of toxic chemicals in a multi-step and energy-intensive fabrication process. ̽��ֱ��Cambridge-developed sensors can be made anywhere and use a tiny fraction of the energy that regular sensors require.

̽��ֱ��bioelectronic fibres, which are repairable, can be simply washed away when they have reached the end of their useful lifetime, and generate less than a single milligram of waste: by comparison, a typical single load of laundry produces between 600 and 1500 milligrams of fibre waste.

��Using our simple fabrication technique, we can put sensors almost anywhere and repair them where and when they need it, without needing a big printing machine or a centralised manufacturing facility,�� said Huang. ��These sensors can be made on-demand, right where they��re needed, and produce minimal waste and emissions.��

̽��ֱ��researchers say their devices could be used in applications from health monitoring and virtual reality, to precision agriculture and environmental monitoring. In future, other functional materials could be incorporated into this fibre printing method, to build integrated fibre sensors for augmenting the living systems with display, computation, and energy conversion functions. ̽��ֱ��research is being commercialised with the support of Cambridge Enterprise, the ̽��ֱ��s commercialisation arm.

̽��ֱ��research was supported in part by the European Research Council, Wellcome, the Royal Society, and the Biotechnology and Biological Sciences Research Council (BBSRC), part of UK Research and Innovation (UKRI).

Reference:
Wenyu Wang et al. ��Sustainable and imperceptible augmentation of living structures with organic bioelectronic fibres.�� Nature Electronics (2024). DOI: 10.1038/s41928-024-01174-4

Researchers have developed a method to make adaptive and eco-friendly sensors that can be directly and imperceptibly printed onto a wide range of biological surfaces, whether that��s a finger or a flower petal.

Huang Lab, Cambridge

Sensors printed on human fingers

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright ? ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways �C 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

New method developed for ��up-sizing�� mini organs used in medical research

sc604 — Mon, 08 Feb 2021 17:16:20 +0000

̽��ֱ��researchers, from the ̽��ֱ�� of Cambridge, used their method to culture and grow a ��mini-airway��, the first time that a tube-shaped organoid has been developed without the need for any external support.

Using a mould made of a specialised polymer, the researchers were able to guide the size and shape of the mini-airway, grown from adult mouse stem cells, and then remove it from the mould when it reached the point where it could support itself.

Whereas the organoids currently used in medical research are at the microscopic scale, the method developed by the Cambridge team could make it possible to grow life-sized versions of organs. Their results are reported in the journal Advanced Science.

Organoids are tiny, three-dimensional cell assemblies that mimic the cell arrangement of fully-grown organs. They can be a useful way to study human biology and how it can go wrong in various diseases, and possibly how to develop personalised or regenerative treatments. However, assembling them into larger organ structures remains a challenge.

Other research teams have experimented with 3D printing techniques to develop larger mini-organs, but these often require an external support structure.

��Mini-organs are very small and highly fragile,�� said Dr Yan Yan Shery Huang from Cambridge��s Department of Engineering, who co-led the research. ��In order to scale them up, which would increase their usefulness in medical research, we need to find the right conditions to help the cells self-organise.��

Huang and her colleagues have proposed a new organoid engineering approach called Multi-Organoid Patterning and Fusion (MOrPF) to grow a miniature version of a mouse airway using stem cells. Using this technique, the scientists achieved faster assembly of organoids into airway tubes with uninterrupted passageways. ̽��ֱ��mini-airways grown using the MOrPF technique showed potential for scaling up to match living organ structures in size and shape, and retained their shape even in the absence of an external support.

̽��ֱ��MOrPF technique involves several steps. First, a polymer mould �C like a miniature version of a cake or jelly mould �C is used to shape a cluster of many small organoids. ̽��ֱ��cluster is released from the mould after one day, and then grown for a further two weeks. ̽��ֱ��cluster becomes one single tubular structure, covered by an outer layer of airway cells. ̽��ֱ��moulding process is just long enough for the outer layer of the cells to form an envelope around the entire cluster. During the two weeks of further growth, the inner walls gradually disappear, leading to a hollow tubular structure.

��Gradual maturation of the cells is really important,�� said Dr Joo-Hyeon Lee from Cambridge��s Wellcome �C MRC Cambridge Stem Cell Institute, who co-led the research. �� ̽��ֱ��cells need to be well-organised before we can release them so that the structures don��t collapse.��

̽��ֱ��organoid cluster can be thought of like soap bubbles, initially packed together to form to the shape of the mould. In order to fuse into a single gigantic bubble from the cluster of compressed bubbles, the inner walls need to be broken down. In the MOrPF process, the fused organoid clusters are released from the mould to grow in floating, scaffold-free conditions, so that the cells forming the inner walls of the fused cluster can be taken out of the cluster. ̽��ֱ��mould can be made into different sizes or shapes, so that the researchers can pre-determine the shape of the finished mini-organ.

�� ̽��ֱ��interesting thing is, if you think about the soap bubbles, the resulting big bubble is always spherical, but the special mechanical properties of the cell membrane of organoids make the resulting fused shape preserve the shape of the mould,�� said co-author Professor Eugene Terentjev from Cambridge��s Cavendish Laboratory.

̽��ֱ��team say their method closely approximated the natural process of organ tube formation in some animal species. They are hopeful that their technique will help create biomimetic organs to facilitate medical research.

̽��ֱ��researchers first plan to use their method to build a three-dimensional ��organ on a chip��, which enables real-time continuous monitoring of cells, and could be used to develop new treatments for disease while reducing the number of animals used in research. Eventually, the technique could also be used with stem cells taken from a patient, in order to develop personalised treatments in future.

̽��ֱ��research was supported in part by the European Research Council, the Wellcome Trust and the Royal Society.

Reference:
Ye Liu et al. ��Bio-assembling Macro-Scale, Lumenized Airway Tubes of Defined Shape via Multi-Organoid Patterning and Fusion.�� Advanced Science (2021). DOI: 10.1002/advs.202003332

A team of engineers and scientists has developed a method of ��up-sizing�� organoids: miniature collections of cells which mimic the behaviour of various organs and are promising tools for the study of human biology and disease.?

We need to find the right conditions to help the cells in mini-organs self-organise

Yan Yan Shery Huang

Catherine Dabrowska

3D projection of a multi-organoid aggregate

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright ? ̽��ֱ�� of Cambridge and licensors/contributors as identified.? All rights reserved. We make our image and video content available in a number of ways �C 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 ̽��ֱ�� 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.

̽��ֱ��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. ̽��ֱ��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. ?

̽��ֱ��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.

̽��ֱ��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�� C 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

Yes