Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Flexible, Printable Sensors Detect Underwater Hazards

11.07.2011
Breakthroughs in nanoengineering often involve building new materials or tiny circuits. But a professor at the University of California, San Diego is proving that he can make materials and circuits so flexible that they can be pulled, pushed and contorted – even under water – and still keep functioning properly.

Joseph Wang has successfully printed thick-film electrochemical sensors directly on flexible wetsuit material, paving the way for nano devices to detect underwater explosives or ocean contamination.

“We have a long-term interest in on-body electrochemical monitoring for medical and security applications,” said Wang, a professor in the Department of NanoEngineering in UC San Diego’s Jacobs School of Engineering. “In the past three years we’ve been working on flexible, printable sensors, and the capabilities of our group made it possible to extend these systems for use underwater.”

Wang notes that some members of his team – including electrical-engineering graduate student Joshua Windmiller – are surfers. Given the group’s continued funding from the U.S. Navy, and its location in La Jolla, it was a logical leap to see if it would be possible to print sensors on neoprene, the synthetic-rubber fabric typically used in wetsuits for divers and surfers.

The result: development of “wearable electrochemical sensors for in situ analysis in marine environments.” The paper, published last month in the journal Analyst*, was co-authored by UCSD’s Wang, Windmiller and visiting scholar Gabriela Valdés-Ramírez from Mexico, as well as Michael J. Schöning and Kerstin Malzahn from the Institute of Nano- and Biotechnologies of Germany’s Aachen University of Applied Sciences. (Malzahn is currently a visiting graduate student at UCSD from the German university.)

UCSD has a full U.S. patent pending on the technology, and has begun talks on licensing the system to a Fortune 500 company.

Wang’s 20-person research group is a world leader in the field of printable sensors. But to prove that the sensors printed on neoprene could take a beating and continue working, some of Wang’s colleagues took to the water.

“Anyone trying to take chemical readings under the water will typically have to carry a portable analyzer if they want to detect pollutants,” said Wang, whose group is based in the California Institute for Telecommunications and Information Technology (Calit2) at UCSD. “Instead, we printed a three-electrode sensor directly on the arm of the wetsuit, and inside the neoprene we embedded a 3-volt battery and electronics.”

The electrochemical sensors are based on applying voltage to drive a reduction-oxidation (redox) reaction in a target threat or contaminant – which loses or gains electrons – then measuring the current output. The wearable microsystem provides a visual indication and alert if the levels of harmful contaminants or explosives exceed a pre-defined threshold. It does so by mixing different enzymes into the carbon ink layer before printing on the fabric. (For example, if the enzyme tyrosinase interacts with the pollutant phenol, the LED light switches from green to red.)

The electronics are packed into a device known as a potentiostat that is barely 19mm by 19mm. (The battery is stored on the reverse side of the circuit board.)

In the experiments described in the Analyst article, Wang and his team tested sensors for three potential hazards: a toxic metal (copper); a common industrial pollutant, phenol; and an explosive (TNT). The device also has the potential to detect multiple hazards. “In the paper we used only one electrode,” noted Wang, “but you can have an array of electrodes, each with its own reagent to detect simultaneously multiple contaminants.”

The researchers believe that neoprene is a particularly good fabric on which to print sensors because it is elastic and repels water. It permits high-resolution printing with no apparent defects.

The UCSD team tested the sensor for explosives because of the security hazard highlighted by the 2000 attack on the USS Cole in Yemen. The Navy commonly checks for underwater explosives using a bulky device that a diver must carry underwater to scan the ship’s hull. Using the microsystem developed by Wang and his team, the sensor printed on a wetsuit can quickly and easily alert the diver to nearby explosives.

Wang’s lab has extensive experience printing sensors on flexible fabrics, most recently demonstrating that biosensors printed on the rubber waistband of underwear can be used continuously to monitor the vital signs of soldiers or athletes. The researchers were uncertain, however, about whether bending the printed sensors under water – and in seawater – would still let them continue functioning properly.

In the end, even underwater, and with bending and other deformations, the sensors continued to perform well. “We still need to validate and test it with the Navy,” said Wang. “While the primary security interest will be in the detection of explosives, the Navy in San Diego bay has also detected large concentrations of toxic metals from the paint on Navy ships, so in principle we should be able to print sensors that can detect metals and explosives simultaneously.”

Wang’s work in flexible sensors grew out of 20 years’ experience with innovations in glucose monitoring, ultimately in the form of flexible glucose strips that now account for a $10 billion market worldwide.

Work on the underwater sensors was supported by the Office of Naval Research.

* Wearable electrochemical sensors for in situ analysis in marine environments, Kerstin Malzahn, Joshua Ray Windmiller, Gabriela Valdés-Ramírez, Michael J. Schöning and Joseph Wang, Analyst, June 2011.

Doug Ramsey | Newswise Science News
Further information:
http://www.ucsd.edu

More articles from Power and Electrical Engineering:

nachricht Smart windows that self-illuminate on rainy days
29.05.2020 | Pohang University of Science & Technology (POSTECH)

nachricht Skoltech scientists get a sneak peek of a key process in battery 'life'
28.05.2020 | Skolkovo Institute of Science and Technology (Skoltech)

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

Black nitrogen: Bayreuth researchers discover new high-pressure material and solve a puzzle of the periodic table

29.05.2020 | Materials Sciences

Argonne researchers create active material out of microscopic spinning particles

29.05.2020 | Materials Sciences

Smart windows that self-illuminate on rainy days

29.05.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>