̽��ֱ�� of Cambridge - King Abdullah ̽��ֱ�� of Science and Technology (KAUST)

Easy-to-make, ultra-low-power electronics could charge out of thin air

Anonymous — Tue, 13 Oct 2020 11:25:02 +0000

Electronics that consume tiny amounts of power are key for the development of the Internet of Things, in which everyday objects are connected to the internet. Many emerging technologies, from wearables to healthcare devices to smart homes and smart cities, need cost-effective transistors and electronic circuits that can function with minimal energy use.

Printed electronics are a simple and inexpensive way to manufacture electronics that could pave the way for low-cost electronic devices on unconventional substrates – such as clothes, plastic wrap or paper – and provide everyday objects with ‘intelligence’.

However, these devices need to operate with low energy and power consumption to be useful for real-world applications. Although printing techniques have advanced considerably, power consumption has remained a challenge – the different solutions available were too complex for commercial production.

Now, researchers from the ̽��ֱ�� of Cambridge, working with collaborators from China and Saudi Arabia, have developed an approach for printed electronics that could be used to make low-cost devices that recharge out of thin air. Even the ambient radio signals that surround us would be enough to power them. Their results are published in the journal ACS Nano.

Since the commercial batteries which power many devices have limited lifetimes and negative environmental impacts, researchers are developing electronics that can operate autonomously with ultra-low levels of energy.

̽��ֱ��technology developed by the researchers delivers high-performance electronic circuits based on thin-film transistors which are ‘ambipolar’ as they use only one semiconducting material to transport both negative and positive electric charges in their channels, in a region of operation called ‘deep subthreshold’ – a phrase that essentially means that the transistors are operated in a region that is conventionally regarded as their ‘off’ state. ̽��ֱ��team coined the phrase ‘deep-subthreshold ambipolar’ to refer to unprecedented ultra-low operating voltages and power consumption levels.

If electronic circuits made of these devices were to be powered by a standard AA battery, the researchers say it would be possible that they could run for millions of years uninterrupted.

̽��ֱ��team, which included researchers from Soochow ̽��ֱ��, the Chinese Academy of Sciences, ShanghaiTech ̽��ֱ��, and King Abdullah ̽��ֱ�� of Science and Technology (KAUST), used printed carbon nanotubes – ultra-thin cylinders of carbon – as an ambipolar semiconductor to achieve the result.

“Thanks to deep-subthreshold ambipolar approach, we created printed electronics that meet the power and voltage requirements of real-world applications, and opened up opportunities for remote sensing and ‘place-and-forget’ devices that can operate without batteries for their entire lifetime,” said co-lead author Luigi Occhipinti from Cambridge’s Department of Engineering. “Crucially, our ultra-low-power printed electronics are simple and cost-effective to manufacture and overcome long-standing hurdles in the field.”

“Our approach to printed electronics could be scaled up to make inexpensive battery-less devices that could harvest energy from the environment, such as sunlight or omnipresent ambient electromagnetic waves, like those created by our mobile phones and wifi stations,” said co-lead author Professor Vincenzo Pecunia from Soochow ̽��ֱ��. Pecunia is a former PhD student and postdoctoral researcher at Cambridge’s Cavendish Laboratory.

̽��ֱ��work paves the way for a new generation of self-powered electronics for biomedical applications, smart homes, infrastructure monitoring, and the exponentially-growing Internet of Things device ecosystem.

̽��ֱ��research was funded in part by the Engineering and Physical Sciences Research Council (EPSRC).

Reference:
L. Portilla et al. ‘Ambipolar Deep-Subthreshold Printed-Carbon-Nanotube Transistors for Ultralow-Voltage and Ultralow-Power Electronics.’ ACS Nano (2020). DOI: 10.1021/acsnano.0c06619

Researchers have developed a new approach to printed electronics that allows ultra-low-power electronic devices which could recharge from ambient light or radiofrequency noise. ̽��ֱ��approach paves the way for low-cost printed electronics that could be seamlessly embedded in everyday objects and environments.

Luis Portilla

Artist's impression of a hybrid-nanodielectric-based printed-CNT transistor

̽��ֱ��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 – 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.

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Low-cost plastic sensors could monitor a range of health conditions

sc604 — Fri, 22 Jun 2018 18:00:00 +0000

̽��ֱ��sensor can measure the amount of critical metabolites, such as lactate or glucose, that are present in sweat, tears, saliva or blood, and, when incorporated into a diagnostic device, could allow health conditions to be monitored quickly, cheaply and accurately. ̽��ֱ��new device has a far simpler design than existing sensors, and opens up a wide range of new possibilities for health monitoring down to the cellular level. ̽��ֱ��results are reported in the journal Science Advances.

̽��ֱ��device was developed by a team led by the ̽��ֱ�� of Cambridge and King Abdullah ̽��ֱ�� of Science and Technology (KAUST) in Saudi Arabia. Semiconducting plastics such as those used in the current work are being developed for use in solar cells and flexible electronics, but have not yet seen widespread use in biological applications.

“In our work, we’ve overcome many of the limitations of conventional electrochemical biosensors that incorporate enzymes as the sensing material,” said lead author Dr Anna-Maria Pappa, a postdoctoral researcher in Cambridge’s Department of Chemical Engineering and Biotechnology. “In conventional biosensors, the communication between the sensor’s electrode and the sensing material is not very efficient, so it’s been necessary to add molecular wires to facilitate and ‘boost’ the signal.”

To build their sensor, Pappa and her colleagues used a newly-synthesised polymer developed at Imperial College that acts as a molecular wire, directly accepting the electrons produced during electrochemical reactions. When the material comes into contact with a liquid such as sweat, tears or blood, it absorbs ions and swells, becoming merged with the liquid. This leads to significantly higher sensitivity compared to traditional sensors made of metal electrodes.

Additionally, when the sensors are incorporated into more complex circuits, such as transistors, the signal can be amplified and respond to tiny fluctuations in metabolite concentration, despite the tiny size of the devices.

Initial tests of the sensors were used to measure levels of lactate, which is useful in fitness applications or to monitor patients following surgery. However, according to the researchers, the sensor can be easily modified to detect other metabolites, such as glucose or cholesterol by incorporating the appropriate enzyme, and the concentration range that the sensor can detect can be adjusted by changing the device’s geometry.

“This is the first time that it’s been possible to use an electron accepting polymer that can be tailored to improve communication with the enzymes, which allows for the direct detection of a metabolite: this hasn’t been straightforward until now,” said Pappa. “It opens up new directions in biosensing, where materials can be designed to interact with a specific metabolite, resulting in far more sensitive and selective sensors.”

Since the sensor does not consist of metals such as gold or platinum, it can be manufactured at a lower cost and can be easily incorporated in flexible and stretchable substrates, enabling their implementation in wearable or implantable sensing applications.

“An implantable device could allow us to monitor the metabolic activity of the brain in real time under stress conditions, such as during or immediately before a seizure and could be used to predict seizures or to assess treatment,” said Pappa.

̽��ֱ��researchers now plan to develop the sensor to monitor metabolic activity of human cells in real time outside the body. ̽��ֱ��Bioelectronic Systems and Technologies group where Pappa is based is focused on developing models that can closely mimic our organs, along with technologies that can accurately assess them in real-time. ̽��ֱ��developed sensor technology can be used with these models to test the potency or toxicity of drugs.

̽��ֱ��research was funded by the Marie Curie Foundation, the KAUST Office of Sponsored Research, and the Engineering and Physical Sciences Research Council.

Reference:
A.M. Pappa et al. ‘Direct metabolite detection with an n-type accumulation mode organic electrochemical transistor.’ Science Advances (2018). DOI: 10.1126/sciadv.aat0911

An international team of researchers have developed a low-cost sensor made from semiconducting plastic that can be used to diagnose or monitor a wide range of health conditions, such as surgical complications or neurodegenerative diseases.

This work opens up new directions in biosensing, where materials can be designed to interact with a specific metabolite, resulting in far more sensitive and selective sensors.

Anna-Maria Pappa

KAUST

Polymer biosensor

Researcher profile: Anna Maria Pappa

I strongly believe that through diversity comes creativity, comes progress. I qualified as an engineer, and later earned my Master’s degree at Aristotle ̽��ֱ�� of Thessaloniki in Greece. My PhD is in Bioelectronics from École des Mines de Saint-Étienne in France and leaving my comfort zone to study abroad proved to be an invaluable experience. I met people from different cultures and mindsets from all over the world, stretched my mind and expanded my horizons.

Now, I always look for those with different views. I travel frequently for conferences and visit other laboratories across Europe, the United States and Saudi Arabia. When you work in a multidisciplinary field it is essential to establish and keep good collaborations: this is the only way to achieve the desired outcome.

Being part of a ̽��ֱ�� where some of the world's most brilliant scientists studied and worked is a great privilege. Cambridge combines a historic and traditional atmosphere with cutting-edge research in an open, multicultural society. ̽��ֱ��state-of-the-art facilities, the openness in innovation and strong collaborations provide a unique combination that can only lead to excellence.

As an engineer, creating solutions to important yet unresolved issues for healthcare is what truly motivates me. I’m working on a drug discovery platform using bioelectronics, and my work sets out to improve and accelerate drug discovery by providing novel technological solutions for drug screening and disease management. I hope my research will lead to a product that will impact healthcare. In the future, I imagine a healthcare system where the standard one-size-fits-all approach shifts to a more personalised and tailored model.

I’m a strong advocate for Women in STEMM, and in October 2017 I was awarded a L'Oréal-UNESCO For Women in Science Fellowship, an award that honours the contributions of women in science. For me, the award not only represents a scientific distinction but also gives me the unique opportunity, as an ambassador of science, to inspire and motivate young girls to follow the career they desire.

I think it’s absolutely vital, at every opportunity, for all of us to honour and promote girls and women in science. Unfortunately, women still struggle when it comes to joining male-dominated fields, and even to establish themselves later at senior roles. We still face stereotypes and social restrictions, even if it is not as obvious today as it was in the past. A question I always ask girls during my outreach activities at schools, is, ‘do I look like a scientist?’, and the answer I most often get is no! I think this misperception of what STEMM professionals look like, or of what they actually do on a daily basis is what discourages girls early on to follow STEMM careers. This needs to change.

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