Tag Archives: monitoring patch

A tattoo that’s a biobattery and a sensor?

It’s going to be an American Chemical Society (ACS) 248th meeting kind of week as yet another interesting piece of scientific research is bruited (spread) about the internet. This time it’s all about sweat, exercise, and biobatteries. From an Aug. 13, 2014 news item on Nanowerk,

In the future, working up a sweat by exercising may not only be good for your health, but it could also power your small electronic devices. Researchers will report today that they have designed a sensor in the form of a temporary tattoo that can both monitor a person’s progress during exercise and produce power from their perspiration.

An Aug. 13, 2014 ACS news release on EurekAlert, which originated the news item, describes the inspiration (as opposed to perspiration) for this technology,

The device works by detecting and responding to lactate, which is naturally present in sweat. “Lactate is a very important indicator of how you are doing during exercise,” says Wenzhao Jia, Ph.D.

In general, the more intense the exercise, the more lactate the body produces. During strenuous physical activity, the body needs to generate more energy, so it activates a process called glycolysis. Glycolysis produces energy and lactate, the latter of which scientists can detect in the blood.

Professional athletes monitor their lactate levels during performance testing as a way to evaluate their fitness and training program. In addition, doctors measure lactate during exercise testing of patients for conditions marked by abnormally high lactate levels, such as heart or lung disease. Currently, lactate testing is inconvenient and intrusive because blood samples must be collected from the person at different times during the exercise regime and then analyzed.

The news release goes on to describe the research process which resulted in a temporary tattoo that could be used to power small scale electronics,

Jia, a postdoctoral student in the lab of Joseph Wang, D.Sc., at the University of California San Diego, and her colleagues developed a faster, easier and more comfortable way to measure lactate during exercise. They imprinted a flexible lactate sensor onto temporary tattoo paper. The sensor contained an enzyme that strips electrons from lactate, generating a weak electrical current. The researchers applied the tattoo to the upper arms of 10 healthy volunteers. Then the team measured the electrical current produced as the volunteers exercised at increasing resistance levels on a stationary bicycle for 30 minutes. In this way, they could continuously monitor sweat lactate levels over time and with changes in exercise intensity.

The team then went a step further, building on these findings to make a sweat-powered biobattery. Batteries produce energy by passing current, in the form of electrons, from an anode to a cathode. In this case, the anode contained the enzyme that removes electrons from lactate, and the cathode contained a molecule that accepts the electrons.

When 15 volunteers wore the tattoo biobatteries while exercising on a stationary bike, they produced different amounts of power. Interestingly, people who were less fit (exercising fewer than once a week) produced more power than those who were moderately fit (exercising one to three times per week). Enthusiasts who worked out more than three times per week produced the least amount of power. The researchers say that this is probably because the less-fit people became fatigued sooner, causing glycolysis to kick in earlier, forming more lactate. The maximum amount of energy produced by a person in the low-fitness group was 70 microWatts per cm2 of skin.

“The current produced is not that high, but we are working on enhancing it so that eventually we could power some small electronic devices,” Jia says. “Right now, we can get a maximum of 70 microWatts per cm2, but our electrodes are only 2 by 3 millimeters in size and generate about 4 microWatts — a bit small to generate enough power to run a watch, for example, which requires at least 10 microWatts. So besides working to get higher power, we also need to leverage electronics to store the generated current and make it sufficient for these requirements.”

Biobatteries offer certain advantages over conventional batteries: They recharge more quickly, use renewable energy sources (in this case, sweat), and are safer because they do not explode or leak toxic chemicals.

“These represent the first examples of epidermal electrochemical biosensing and biofuel cells that could potentially be used for a wide range of future applications,” Wang says.

The ACS has made a video about this work available,

It seems to me this tattoo battery could be used as a self-powered monitoring device in a medical application for heart or lung disease.

Nano-Bio Manufacturing Consortium’s request for proposals (RFPs) on human performance monitoring platforms

The requested human performance monitor platform RFPs are for a US Air Force Research Laboratory (AFRL) project being managed by the Nano-Bio Manufacturing Consortium (NBMC), according to a July 17, 2013 news item on Nanowerk,

The Nano-Bio Manufacturing Consortium (NBMC) has released its first Request for Proposals (RFP) focused on developing a technology platform for Human Performance Monitors for military and civilian personnel in high stress situations such as pilots, special operations personnel, firefighters, and trauma care providers. Organized by FlexTech Alliance under a grant from the U.S. Air Force Research Laboratory (AFRL) the RFP comes only 3 month since the group officially formed its technical and leadership teams. The consortium members, working with AFRL, issued this RFP to focus on component development and integration for a lightweight, low-cost, conformal and wearable patch.

The July 17, 2013 NBMC news release, which originated the news item, offers more about this patch/monitor,

The heart of this new patch will be a biosensor device to measure chemicals, called biomarkers, in human sweat.  These biomarkers can provide early warnings of performance issues such as stress, fatigue, vigilance or organ damage.  The platform will contain the sensor, a microfluidic system that delivers sweat to the sensor, printed and hybrid control electronics, interconnects, a power supply, wireless communication, and software – all on a flexible substrate that is comfortable to wear.

“An aircraft has numerous sensors which take over 1500 measurements per second to monitor its condition in flight, whereas the most critical part – the pilot – has no monitors,” Malcolm Thompson, chief executive officer of NBMC stated.  “We are working quickly and efficiently to coordinate the expertise being generated at an array of companies, government labs and academic centers.  NBMC’s goal is to establish this technology chain to more rapidly develop products and manufacturing approaches for the Air Force and commercial markets.”

I gather the reasoning is that we should be able to monitor human beings just as we do equipment and machines.

The news release also offers information about the consortium partners,

Initial consortium membership includes a wide range of organizations.  Fortune 500 technology leaders include General Electric, Lockheed Martin, and DuPont Teijin Films.  More entrepreneurial organizations include PARC (a Xerox Company), MC 10, Soligie, American Semiconductor, Brewer Science and UES.  They are joined by the Air Force Research Laboratory and university leaders such as Cornell University, University of Massachusetts Amherst Center for Hierarchical Manufacturing, University of Arizona Center for Integrative Medicine, UC San Diego, University of Cincinnati, Binghamton University, Johns Hopkins University, Northeastern University NSF Nanoscale Science and Engineering Center for High-rate Nano-manufacturing, and Arizona State University.

The NBMC solicitation was posted July 10, 2013 on this page,

2013 SOLICITATION ON HUMAN PERFORMANCE MONITORING & BIOMARKER DETECTION

Request for Proposals Issued: July 10th, 2013

Proposals Due Date: August 9th, 2013 – 5:00 PM PDT

You can find the 9pp RFP here.

I’ve decided to include this description of the thinking that underlies the consortium, from the NBMC Nano-Bio Manufacturing webpage,

The field of nano-biotechnology is advancing rapidly, with many important discoveries and potential applications being identified.  Much of this work is taking place in academia and advanced research labs around the globe.  Once an application is identified, however, the road is still long to making it available to the markets in need.  One of the final steps on that road is understanding how to manufacture in high volume and the lowest cost.  Often this is the defining decision on whether the product even gets to that market.

With new nano-bio technology solutions, the challenges to produce in volume at low-cost are entirely new to many in the field.  New materials, new substrates, new equipment, and unknown properties are just a few of the hurdles that no one organization has been able to overcome.

To address these challenges, FlexTech Alliance, in collaboration with a nationwide group of partners, has formed a Nano-Bio Manufacturing Consortium (NBMC) for the U.S. Air Force Research Laboratory (AFRL). The mission of this partnership is to bring together leading scientists, engineers, and business development professionals from industry and universities in order to work collaboratively in a consortium, and to mature an integrated suite of nano-bio manufacturing technologies to transition to industrial manufacturing.

Initial activities focus on AFRL/ DoD priorities, e.g., physiological readiness and human performance monitoring. Specifically, NBMC matures nano-bio manufacturing technologies to create an integrated suite of reconfigurable and digitized fabrication methods that are compatible with biological and nanoparticle materials and to transition thin film, mechanically compliant device concepts through a foundry-like manufacturing flow.

The long-term vision is that NBMC operates at the confluence of four core emerging disciplines: nanotechnology, biotechnology, advanced (additive) manufacturing, and flexible electronics. The convergence of these disparate fields enables advanced sensor architectures for real-time, remote physiological and health/medical monitoring.

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It seems to me that human beings are increasingly being viewed as just another piece of equipment.