Tag Archives: Zhong Lin Wang

Mechano-photonic artificial synapse is bio-inspired

The word ‘memristor’ usually pops up when there’s research into artificial synapses but not in this new piece of research. I didn’t see any mention of the memristor in the paper’s references either but I did find James Gimzewski from the University of California at Los Angeles (UCLA) whose research into brainlike computing (neuromorphic computing) is running parallel but separately to the memristor research.

Dr. Thamarasee Jeewandara has written a March 25, 2021 article for phys.org about the latest neuromorphic computing research (Note: Links have been removed)

Multifunctional and diverse artificial neural systems can incorporate multimodal plasticity, memory and supervised learning functions to assist neuromorphic computation. In a new report, Jinran Yu and a research team in nanoenergy, nanoscience and materials science in China and the US., presented a bioinspired mechano-photonic artificial synapse with synergistic mechanical and optical plasticity. The team used an optoelectronic transistor made of graphene/molybdenum disulphide (MoS2) heterostructure and an integrated triboelectric nanogenerator to compose the artificial synapse. They controlled the charge transfer/exchange in the heterostructure with triboelectric potential and modulated the optoelectronic synapse behaviors readily, including postsynaptic photocurrents, photosensitivity and photoconductivity. The mechano-photonic artificial synapse is a promising implementation to mimic the complex biological nervous system and promote the development of interactive artificial intelligence. The work is now published on Science Advances.

The human brain can integrate cognition, learning and memory tasks via auditory, visual, olfactory and somatosensory interactions. This process is difficult to be mimicked using conventional von Neumann architectures that require additional sophisticated functions. Brain-inspired neural networks are made of various synaptic devices to transmit information and process using the synaptic weight. Emerging photonic synapse combine the optical and electric neuromorphic modulation and computation to offer a favorable option with high bandwidth, fast speed and low cross-talk to significantly reduce power consumption. Biomechanical motions including touch, eye blinking and arm waving are other ubiquitous triggers or interactive signals to operate electronics during artificial synapse plasticization. In this work, Yu et al. presented a mechano-photonic artificial synapse with synergistic mechanical and optical plasticity. The device contained an optoelectronic transistor and an integrated triboelectric nanogenerator (TENG) in contact-separation mode. The mechano-optical artificial synapses have huge functional potential as interactive optoelectronic interfaces, synthetic retinas and intelligent robots. [emphasis mine]

As you can see Jeewandara has written quite a technical summary of the work. Here’s an image from the Science Advances paper,

Fig. 1 Biological tactile/visual neurons and mechano-photonic artificial synapse. (A) Schematic illustrations of biological tactile/visual sensory system. (B) Schematic diagram of the mechano-photonic artificial synapse based on graphene/MoS2 (Gr/MoS2) heterostructure. (i) Top-view scanning electron microscope (SEM) image of the optoelectronic transistor; scale bar, 5 μm. The cyan area indicates the MoS2 flake, while the white strip is graphene. (ii) Illustration of charge transfer/exchange for Gr/MoS2 heterostructure. (iii) Output mechano-photonic signals from the artificial synapse for image recognition.

You can find the paper here,

Bioinspired mechano-photonic artificial synapse based on graphene/MoS2 heterostructure by Jinran Yu, Xixi Yang, Guoyun Gao, Yao Xiong, Yifei Wang, Jing Han, Youhui Chen, Huai Zhang, Qijun Sun and Zhong Lin Wang. Science Advances 17 Mar 2021: Vol. 7, no. 12, eabd9117 DOI: 10.1126/sciadv.abd9117

This appears to be open access.

Institute for Electrical and Electronics Engineers’ (IEEE) Nano 2015 conference call for papers

The institute for Electrical and Electronics Engineers is holding its Nano 2015 conference in Rome, Italy from July 27 – 30, 2015. This is the second call for papers (I missed the first call),

We invite you to submit papers, proposals for tutorials, workshops to the International IEEE Conference on Nanotechnology which will be held in Rome, July 27-30, 2015. (See www.ieeenano15.org). The dead-line for abstract submission is 15th March 2015.

This conference is the 15th edition of the flagship annual event of the IEEE Nanotechnology Council. IEEE NANO 2015 will provide an international forum for the exchange of technical information in a wide variety of branches of Nanotechnology and Nanoscience, through feature tutorials, workshops, track sessions and special sessions; plenary and invited talks from the most renowned scientists and engineers; exhibition of software, hardware, equipment, materials, services and literature. With its fantastic setting in the centre of the Eternal City, at a walking distance from Colosseum and from the most exciting locations of ancient Rome, IEEE NANO 2015 will provide a perfect forum for inspiration, interactions and exchange of ideas.

All accepted papers will be published by IEEE Press, included in IEEE Xplore and Indexed by EI. Selected conference papers will be considered for publication on IEEE Transactions on Nanotechnology.

Important Dates

March 15, 2015:       Tutorial/Workshop Proposal
March 15, 2015:        Abstract Submission
April 15, 2015:           Acceptance Notification

May 15, 2015:            Full Paper Submission
June 1, 2015:              End of early Registration

Topics for contributing papers include but are not limited to:

Nanosensors, Actuators
Smart systems
Nanomaterials
Graphene-Based Materials
Nano-energy, Energy Harvesting
Nanobiology, Nanobiotechnology
Nanomedicine
Nanoelectronics
Nano-optoelectronics
MEMS/NEMS
Nano-optics, Nano-photonics
Nano-electromagnetics, NanoEMC
Nanofabrication, Nanoassemblies
Nanopackaging
Nanorobotics, Nanomanipulation
Nanometrology
Nanocharacterization
Nanofluidics
Nanomagnetics
Multiscale Modeling and Simulation

PLENARY SPEAKERS (See www.ieeenano15.org/program/plenary-speakers)
George Bourianoff, Intel (USA)
Michael Grätzel, EPFL (Switzerland)
Roberto Cingolani, IIT (Italy)
Rodney Ruoff, NIST (Korea)
Takao Someya, Tokyo Univ. (Japan)
Theresa Mayer, Pennsylvania State Univ. (USA)
Zhong Lin Wang, Georgia Tech (USA)

Proposed SPECIAL SESSIONS
1) Graphene
2) Nanoelectromagnetics and Nano-EMC
3) Nanometrology and device characterization
4) Nanotechnology for microwave and THz
5) Memristor
Part 1: Resistive switching: from fundamentals to production
Part 2: Memristive nanodevices and nanocircuits
6) Nanophononics
7) Drug Toxicity Mitigation. Nanotechnology-Enabled Strategies
8) Conformable Electronics and E-Skin
9) Organic Neurooptoelectronics

There are more details about the call in this PDF. Good luck!

The perfect keyboard: it self-cleans and self-powers and it can identify its owner(s)

There’s a pretty nifty piece of technology being described in a Jan. 21, 2015 news item on Nanowerk, which focuses on the security aspects first (Note: A link has been removed),

In a novel twist in cybersecurity, scientists have developed a self-cleaning, self-powered smart keyboard that can identify computer users by the way they type. The device, reported in the journal ACS Nano (“Personalized Keystroke Dynamics for Self-Powered Human–Machine Interfacing”), could help prevent unauthorized users from gaining direct access to computers.

A Jan. 21, 2015 American Chemical Society (ACS) news release (also on EurekAlert), which originated the news item, continues with the keyboard’s security features before briefly mentioning the keyboard’s self-powering and self-cleaning capabilities,

Zhong Lin Wang and colleagues note that password protection is one of the most common ways we control who can log onto our computers — and see the private information we entrust to them. But as many recent high-profile stories about hacking and fraud have demonstrated, passwords are themselves vulnerable to theft. So Wang’s team set out to find a more secure but still cost-effective and user-friendly approach to safeguarding what’s on our computers.

The researchers developed a smart keyboard that can sense typing patterns — including the pressure applied to keys and speed — that can accurately distinguish one individual user from another. So even if someone knows your password, he or she cannot access your computer because that person types in a different way than you would. It also can harness the energy generated from typing to either power itself or another small device. And the special surface coating repels dirt and grime. The scientists conclude that the keyboard could provide an additional layer of protection to boost the security of our computer systems.

Here’s a link to and a citation for the paper,

Personalized Keystroke Dynamics for Self-Powered Human–Machine Interfacing by Jun Chen, Guang Zhu, Jin Yang, Qingshen Jing, Peng Bai, Weiqing Yang, Xuewei Qi, Yuanjie Su, and Zhong Lin Wang. ACS Nano, Article ASAP DOI: 10.1021/nn506832w Publication Date (Web): December 30, 2014

Copyright © 2014 American Chemical Society

This paper is behind a paywall. I did manage a peek at the paper and found that the keyboard is able to somehow harvest the mechanical energy of typing and turn it into electricity so it can self-power. Self-cleaning is made possible by a nanostructure surface modification. An idle thought and a final comment. First, I wonder what happens if you want to or have to share your keyboard? Second, a Jan. 21, 2015 article about the intelligent keyboard by Luke Dormehl for Fast Company notes that the researchers are from the US and China and names two of the institutions involved in this collaboration, Georgia Institute of Technology and the Beijing Institute of Nanoenergy and Nanosystems,.

ETA Jan. 23, 2015: There’s a Georgia Institute of Technology Jan. 21, 2015 news release on EurekAlert about the intelligent keyboard which offers more technical details such as these,

Conventional keyboards record when a keystroke makes a mechanical contact, indicating the press of a specific key. The intelligent keyboard records each letter touched, but also captures information about the amount of force applied to the key and the length of time between one keystroke and the next. Such typing style is unique to individuals, and so could provide a new biometric for securing computers from unauthorized use.

In addition to providing a small electrical current for registering the key presses, the new keyboard could also generate enough electricity to charge a small portable electronic device or power a transmitter to make the keyboard wireless.

An effect known as contact electrification generates current when the user’s fingertips touch a plastic material on which a layer of electrode material has been coated. Voltage is generated through the triboelectric and electrostatic induction effects. Using the triboelectric effect, a small charge can be produced whenever materials are brought into contact and then moved apart.

“Our skin is dielectric and we have electrostatic charges in our fingers,” Wang noted. “Anything we touch can become charged.”

Instead of individual mechanical keys as in traditional keyboards, Wang’s intelligent keyboard is made up of vertically-stacked transparent film materials. Researchers begin with a layer of polyethylene terephthalate between two layers of indium tin oxide (ITO) that form top and bottom electrodes.

Next, a layer of fluorinated ethylene propylene (FEP) is applied onto the ITO surface to serve as an electrification layer that generates triboelectric charges when touched by fingertips. FEP nanowire arrays are formed on the exposed FEP surface through reactive ion etching.

The keyboard’s operation is based on coupling between contact electrification and electrostatic induction, rather than the traditional mechanical switching. When a finger contacts the FEP, charge is transferred at the contact interface, injecting electrons from the skin into the material and creating a positive charge.

When the finger moves away, the negative charges on the FEP side induces positive charges on the top electrode, and equal amounts of negative charges on the bottom electrode. Consecutive keystrokes produce a periodic electrical field that drives reciprocating flows of electrons between the electrodes. Though eventually dissipating, the charges remain on the FEP surface for an extended period of time.

Wang believes the new smart keyboard will be competitive with existing keyboards, in both cost and durability. The new device is based on inexpensive materials that are widely used in the electronics industry.

Bendable, stretchable, light-weight, and transparent: a new competitor in the competition for ‘thinnest electric generator’

An Oct. 15, 2014 Columbia University (New York, US) press release (also on EurekAlert), describes another contender for the title of the world’s thinnest electric generator,

Researchers from Columbia Engineering and the Georgia Institute of Technology [US] report today [Oct. 15, 2014] that they have made the first experimental observation of piezoelectricity and the piezotronic effect in an atomically thin material, molybdenum disulfide (MoS2), resulting in a unique electric generator and mechanosensation devices that are optically transparent, extremely light, and very bendable and stretchable.

In a paper published online October 15, 2014, in Nature, research groups from the two institutions demonstrate the mechanical generation of electricity from the two-dimensional (2D) MoS2 material. The piezoelectric effect in this material had previously been predicted theoretically.

Here’s a link to and a citation for the paper,

Piezoelectricity of single-atomic-layer MoS2 for energy conversion and piezotronics by Wenzhuo Wu, Lei Wang, Yilei Li, Fan Zhang, Long Lin, Simiao Niu, Daniel Chenet, Xian Zhang, Yufeng Hao, Tony F. Heinz, James Hone, & Zhong Lin Wang. Nature (2014) doi:10.1038/nature13792 Published online 15 October 2014

This paper is behind a paywall. There is a free preview available with ReadCube Access.

Getting back to the Columbia University press release, it offers a general description of piezoelectricity and some insight into this new research on molybdenum disulfide,

Piezoelectricity is a well-known effect in which stretching or compressing a material causes it to generate an electrical voltage (or the reverse, in which an applied voltage causes it to expand or contract). But for materials of only a few atomic thicknesses, no experimental observation of piezoelectricity has been made, until now. The observation reported today provides a new property for two-dimensional materials such as molybdenum disulfide, opening the potential for new types of mechanically controlled electronic devices.

“This material—just a single layer of atoms—could be made as a wearable device, perhaps integrated into clothing, to convert energy from your body movement to electricity and power wearable sensors or medical devices, or perhaps supply enough energy to charge your cell phone in your pocket,” says James Hone, professor of mechanical engineering at Columbia and co-leader of the research.

“Proof of the piezoelectric effect and piezotronic effect adds new functionalities to these two-dimensional materials,” says Zhong Lin Wang, Regents’ Professor in Georgia Tech’s School of Materials Science and Engineering and a co-leader of the research. “The materials community is excited about molybdenum disulfide, and demonstrating the piezoelectric effect in it adds a new facet to the material.”

Hone and his research group demonstrated in 2008 that graphene, a 2D form of carbon, is the strongest material. He and Lei Wang, a postdoctoral fellow in Hone’s group, have been actively exploring the novel properties of 2D materials like graphene and MoS2 as they are stretched and compressed.

Zhong Lin Wang and his research group pioneered the field of piezoelectric nanogenerators for converting mechanical energy into electricity. He and postdoctoral fellow Wenzhuo Wu are also developing piezotronic devices, which use piezoelectric charges to control the flow of current through the material just as gate voltages do in conventional three-terminal transistors.

There are two keys to using molybdenum disulfide for generating current: using an odd number of layers and flexing it in the proper direction. The material is highly polar, but, Zhong Lin Wang notes, so an even number of layers cancels out the piezoelectric effect. The material’s crystalline structure also is piezoelectric in only certain crystalline orientations.

For the Nature study, Hone’s team placed thin flakes of MoS2 on flexible plastic substrates and determined how their crystal lattices were oriented using optical techniques. They then patterned metal electrodes onto the flakes. In research done at Georgia Tech, Wang’s group installed measurement electrodes on samples provided by Hone’s group, then measured current flows as the samples were mechanically deformed. They monitored the conversion of mechanical to electrical energy, and observed voltage and current outputs.

The researchers also noted that the output voltage reversed sign when they changed the direction of applied strain, and that it disappeared in samples with an even number of atomic layers, confirming theoretical predictions published last year. The presence of piezotronic effect in odd layer MoS2 was also observed for the first time.

“What’s really interesting is we’ve now found that a material like MoS2, which is not piezoelectric in bulk form, can become piezoelectric when it is thinned down to a single atomic layer,” says Lei Wang.

To be piezoelectric, a material must break central symmetry. A single atomic layer of MoS2 has such a structure, and should be piezoelectric. However, in bulk MoS2, successive layers are oriented in opposite directions, and generate positive and negative voltages that cancel each other out and give zero net piezoelectric effect.

“This adds another member to the family of piezoelectric materials for functional devices,” says Wenzhuo Wu.

In fact, MoS2 is just one of a group of 2D semiconducting materials known as transition metal dichalcogenides, all of which are predicted to have similar piezoelectric properties. These are part of an even larger family of 2D materials whose piezoelectric materials remain unexplored. Importantly, as has been shown by Hone and his colleagues, 2D materials can be stretched much farther than conventional materials, particularly traditional ceramic piezoelectrics, which are quite brittle.

The research could open the door to development of new applications for the material and its unique properties.

“This is the first experimental work in this area and is an elegant example of how the world becomes different when the size of material shrinks to the scale of a single atom,” Hone adds. “With what we’re learning, we’re eager to build useful devices for all kinds of applications.”

Ultimately, Zhong Lin Wang notes, the research could lead to complete atomic-thick nanosystems that are self-powered by harvesting mechanical energy from the environment. This study also reveals the piezotronic effect in two-dimensional materials for the first time, which greatly expands the application of layered materials for human-machine interfacing, robotics, MEMS, and active flexible electronics.

I see there’s a reference in that last paragraph to “harvesting mechanical energy from  the environment.” I’m not sure what they mean by that but I have written a few times about harvesting biomechanical energy. One of my earliest pieces is a July 12, 2010 post which features work by Zhong Lin Wang on harvesting energy from heart beats, blood flow, muscle stretching, or even irregular vibrations. One of my latest pieces is a Sept. 17, 2014 post about some work in Canada on harvesting energy from the jaw as you chew.

A final note, Dexter Johnson discusses this work in an Oct. 16, 2014 post on the Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website).

Cardiac pacemakers: Korea’s in vivo demonstration of a self-powered one* and UK’s breath-based approach

As i best I can determine ,the last mention of a self-powered pacemaker and the like on this blog was in a Nov. 5, 2012 posting (Developing self-powered batteries for pacemakers). This latest news from The Korea Advanced Institute of Science and Technology (KAIST) is, I believe, the first time that such a device has been successfully tested in vivo. From a June 23, 2014 news item on ScienceDaily,

As the number of pacemakers implanted each year reaches into the millions worldwide, improving the lifespan of pacemaker batteries has been of great concern for developers and manufacturers. Currently, pacemaker batteries last seven years on average, requiring frequent replacements, which may pose patients to a potential risk involved in medical procedures.

A research team from the Korea Advanced Institute of Science and Technology (KAIST), headed by Professor Keon Jae Lee of the Department of Materials Science and Engineering at KAIST and Professor Boyoung Joung, M.D. of the Division of Cardiology at Severance Hospital of Yonsei University, has developed a self-powered artificial cardiac pacemaker that is operated semi-permanently by a flexible piezoelectric nanogenerator.

A June 23, 2014 KAIST news release on EurekAlert, which originated the news item, provides more details,

The artificial cardiac pacemaker is widely acknowledged as medical equipment that is integrated into the human body to regulate the heartbeats through electrical stimulation to contract the cardiac muscles of people who suffer from arrhythmia. However, repeated surgeries to replace pacemaker batteries have exposed elderly patients to health risks such as infections or severe bleeding during operations.

The team’s newly designed flexible piezoelectric nanogenerator directly stimulated a living rat’s heart using electrical energy converted from the small body movements of the rat. This technology could facilitate the use of self-powered flexible energy harvesters, not only prolonging the lifetime of cardiac pacemakers but also realizing real-time heart monitoring.

The research team fabricated high-performance flexible nanogenerators utilizing a bulk single-crystal PMN-PT thin film (iBULe Photonics). The harvested energy reached up to 8.2 V and 0.22 mA by bending and pushing motions, which were high enough values to directly stimulate the rat’s heart.

Professor Keon Jae Lee said:

“For clinical purposes, the current achievement will benefit the development of self-powered cardiac pacemakers as well as prevent heart attacks via the real-time diagnosis of heart arrhythmia. In addition, the flexible piezoelectric nanogenerator could also be utilized as an electrical source for various implantable medical devices.”

This image illustrating a self-powered nanogenerator for a cardiac pacemaker has been provided by KAIST,

This picture shows that a self-powered cardiac pacemaker is enabled by a flexible piezoelectric energy harvester. Credit: KAIST

This picture shows that a self-powered cardiac pacemaker is enabled by a flexible piezoelectric energy harvester.
Credit: KAIST

Here’s a link to and a citation for the paper,

Self-Powered Cardiac Pacemaker Enabled by Flexible Single Crystalline PMN-PT Piezoelectric Energy Harvester by Geon-Tae Hwang, Hyewon Park, Jeong-Ho Lee, SeKwon Oh, Kwi-Il Park, Myunghwan Byun, Hyelim Park, Gun Ahn, Chang Kyu Jeong, Kwangsoo No, HyukSang Kwon, Sang-Goo Lee, Boyoung Joung, and Keon Jae Lee. Advanced Materials DOI: 10.1002/adma.201400562
Article first published online: 17 APR 2014

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

There was a May 15, 2014 KAIST news release on EurekAlert announcing this same piece of research but from a technical perspective,

The energy efficiency of KAIST’s piezoelectric nanogenerator has increased by almost 40 times, one step closer toward the commercialization of flexible energy harvesters that can supply power infinitely to wearable, implantable electronic devices

NANOGENERATORS are innovative self-powered energy harvesters that convert kinetic energy created from vibrational and mechanical sources into electrical power, removing the need of external circuits or batteries for electronic devices. This innovation is vital in realizing sustainable energy generation in isolated, inaccessible, or indoor environments and even in the human body.

Nanogenerators, a flexible and lightweight energy harvester on a plastic substrate, can scavenge energy from the extremely tiny movements of natural resources and human body such as wind, water flow, heartbeats, and diaphragm and respiration activities to generate electrical signals. The generators are not only self-powered, flexible devices but also can provide permanent power sources to implantable biomedical devices, including cardiac pacemakers and deep brain stimulators.

However, poor energy efficiency and a complex fabrication process have posed challenges to the commercialization of nanogenerators. Keon Jae Lee, Associate Professor of Materials Science and Engineering at KAIST, and his colleagues have recently proposed a solution by developing a robust technique to transfer a high-quality piezoelectric thin film from bulk sapphire substrates to plastic substrates using laser lift-off (LLO).

Applying the inorganic-based laser lift-off (LLO) process, the research team produced a large-area PZT thin film nanogenerators on flexible substrates (2 cm x 2 cm).

“We were able to convert a high-output performance of ~250 V from the slight mechanical deformation of a single thin plastic substrate. Such output power is just enough to turn on 100 LED lights,” Keon Jae Lee explained.

The self-powered nanogenerators can also work with finger and foot motions. For example, under the irregular and slight bending motions of a human finger, the measured current signals had a high electric power of ~8.7 μA. In addition, the piezoelectric nanogenerator has world-record power conversion efficiency, almost 40 times higher than previously reported similar research results, solving the drawbacks related to the fabrication complexity and low energy efficiency.

Lee further commented,

“Building on this concept, it is highly expected that tiny mechanical motions, including human body movements of muscle contraction and relaxation, can be readily converted into electrical energy and, furthermore, acted as eternal power sources.”

The research team is currently studying a method to build three-dimensional stacking of flexible piezoelectric thin films to enhance output power, as well as conducting a clinical experiment with a flexible nanogenerator.

In addition to the 2012 posting I mentioned earlier, there was also this July 12, 2010 posting which described research on harvesting biomechanical movement ( heart beat, blood flow, muscle stretching, or even irregular vibration) at the Georgia (US) Institute of Technology where the lead researcher observed,

…  Wang [Professor Zhong Lin Wang at Georgia Tech] tells Nanowerk. “However, the applications of the nanogenerators under in vivo and in vitro environments are distinct. Some crucial problems need to be addressed before using these devices in the human body, such as biocompatibility and toxicity.”

Bravo to the KAIST researchers for getting this research to the in vivo testing stage.

Meanwhile at the University of Bristol and at the University of Bath, researchers have received funding for a new approach to cardiac pacemakers, designed them with the breath in mind. From a June 24, 2014 news item on Azonano,

Pacemaker research from the Universities of Bath and Bristol could revolutionise the lives of over 750,000 people who live with heart failure in the UK.

The British Heart Foundation (BHF) is awarding funding to researchers developing a new type of heart pacemaker that modulates its pulses to match breathing rates.

A June 23, 2014 University of Bristol press release, which originated the news item, provides some context,

During 2012-13 in England, more than 40,000 patients had a pacemaker fitted.

Currently, the pulses from pacemakers are set at a constant rate when fitted which doesn’t replicate the natural beating of the human heart.

The normal healthy variation in heart rate during breathing is lost in cardiovascular disease and is an indicator for sleep apnoea, cardiac arrhythmia, hypertension, heart failure and sudden cardiac death.

The device is then briefly described (from the press release),

The novel device being developed by scientists at the Universities of Bath and Bristol uses synthetic neural technology to restore this natural variation of heart rate with lung inflation, and is targeted towards patients with heart failure.

The device works by saving the heart energy, improving its pumping efficiency and enhancing blood flow to the heart muscle itself.  Pre-clinical trials suggest the device gives a 25 per cent increase in the pumping ability, which is expected to extend the life of patients with heart failure.

One aim of the project is to miniaturise the pacemaker device to the size of a postage stamp and to develop an implant that could be used in humans within five years.

Dr Alain Nogaret, Senior Lecturer in Physics at the University of Bath, explained“This is a multidisciplinary project with strong translational value.  By combining fundamental science and nanotechnology we will be able to deliver a unique treatment for heart failure which is not currently addressed by mainstream cardiac rhythm management devices.”

The research team has already patented the technology and is working with NHS consultants at the Bristol Heart Institute, the University of California at San Diego and the University of Auckland. [emphasis mine]

Professor Julian Paton, from the University of Bristol, added: “We’ve known for almost 80 years that the heart beat is modulated by breathing but we have never fully understood the benefits this brings. The generous new funding from the BHF will allow us to reinstate this natural occurring synchrony between heart rate and breathing and understand how it brings therapy to hearts that are failing.”

Professor Jeremy Pearson, Associate Medical Director at the BHF, said: “This study is a novel and exciting first step towards a new generation of smarter pacemakers. More and more people are living with heart failure so our funding in this area is crucial. The work from this innovative research team could have a real impact on heart failure patients’ lives in the future.”

Given some current events (‘Tesla opens up its patents’, Mike Masnick’s June 12, 2014 posting on Techdirt), I wonder what the situation will be vis à vis patents by the time this device gets to market.

* ‘one’ added to title on Aug. 13, 2014.

Developing self-powered batteries for pacemakers

Imagine having your chest cracked open every time your pacemaker needs to have its battery changed? It’s not a pleasant thought and researchers are working on a number of approaches to change that situation.  Scientists from the University of Michigan have presented the results from some preliminary testing of a device that harvests energy from heartbeats (from the Nov. 4, 2012 news release on EurekAlert),

In a preliminary study, researchers tested an energy-harvesting device that uses piezoelectricity — electrical charge generated from motion. The approach is a promising technological solution for pacemakers, because they require only small amounts of power to operate, said M. Amin Karami, Ph.D., lead author of the study and research fellow in the Department of Aerospace Engineering at the University of Michigan in Ann Arbor.

Piezoelectricity might also power other implantable cardiac devices like defibrillators, which also have minimal energy needs, he said.

Today’s pacemakers must be replaced every five to seven years when their batteries run out, which is costly and inconvenient, Karami said.

A University of Michigan at Ann Arbor March 2, 2012 news release provides more technical detail about this energy-harvesting battery which the researchers had not then tested,

… A hundredth-of-an-inch thin slice of a special “piezoelectric” ceramic material would essentially catch heartbeat vibrations and briefly expand in response. Piezoelectric materials’ claim to fame is that they can convert mechanical stress (which causes them to expand) into an electric voltage.

Karami and his colleague Daniel Inman, chair of Aerospace Engineering at U-M, have precisely engineered the ceramic layer to a shape that can harvest vibrations across a broad range of frequencies. They also incorporated magnets, whose additional force field can drastically boost the electric signal that results from the vibrations.

The new device could generate 10 microwatts of power, which is about eight times the amount a pacemaker needs to operate, Karami said. It always generates more energy than the pacemaker requires, and it performs at heart rates from 7 to 700 beats per minute. That’s well below and above the normal range.

Karami and Inman originally designed the harvester for light unmanned airplanes, where it could generate power from wing vibrations.

Since March 2012, the researchers have tested the prototype (from the Nov. 4, 2012 news release on EurekAlert),

Researchers measured heartbeat-induced vibrations in the chest. Then, they used a “shaker” to reproduce the vibrations in the laboratory and connected it to a prototype cardiac energy harvester they developed. Measurements of the prototype’s performance, based on sets of 100 simulated heartbeats at various heart rates, showed the energy harvester performed as the scientists had predicted — generating more than 10 times the power than modern pacemakers require. The next step will be implanting the energy harvester, which is about half the size of batteries now used in pacemakers, Karami said. Researchers hope to integrate their technology into commercial pacemakers.

There are other teams working on energy-harvesting batteries, in my July 12, 2010 posting I mentioned a team led by Professor Zhong Lin Wang at Georgia Tech (Georgia Institute of Technology in the US) which is working on batteries that harvest energy from biomechanical motion such as heart beats, finger tapping, breathing, etc.