Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists print sensors on gummi candy: creating microelectrode arrays on soft materials

21.06.2018

Microelectrodes can be used for direct measurement of electrical signals in the brain or heart. These applications require soft materials, however. With existing methods, attaching electrodes to such materials poses significant challenges. A team at the Technical University of Munich (TUM) has now succeeded in printing electrodes directly onto several soft substrates.

Researchers from TUM and Forschungszentrum Jülich have successfully teamed up to perform inkjet printing onto a gummy bear. This might initially sound like scientists at play – but it may in fact point the way forward to major changes in medical diagnostics.


Microelectrode arrays on gelatin: A team surrounding Bernhard Wolfrum, Professor of Neuroelectronics at the Technical University of Munich, has successfully printed sensors on gummi candy.

Nouran Adly / TUM

For one thing, it was not an image or logo that Prof. Bernhard Wolfrum's team deposited on the chewy candy, but rather a microelectrode array. These components, comprised of a large number of electrodes, can detect voltage changes resulting from activity in neurons or muscle cells, for example.

Second, gummy bears have a property that is important when using microelectrode arrays in living cells: they are soft. Microelectrode arrays have been around for a long time. In their original form, they consist of hard materials such as silicon.

This results in several disadvantages when they come into contact with living cells. In the laboratory, their hardness affects the shape and organization of the cells, for example. And inside the body, the hard materials can trigger inflammation or the loss of organ functionalities.

Rapid prototyping with inkjet printers

When electrode arrays are placed on soft materials, these problems are avoided. This has sparked intensive research into these solutions. Until now, most initiatives have used traditional methods, which are time-consuming and require access to expensive specialized laboratories. "If you instead print the electrodes, you can produce a prototype relatively quickly and cheaply. The same applies if you need to rework it," says Bernhard Wolfrum, Professor of Neuroelectronics at TUM. "Rapid prototyping of this kind enables us to work in entirely new ways."

Wolfrum and his team work with a high-tech version of an inkjet printer. The electrodes themselves are printed with carbon-based ink. To prevent the sensors from picking up stray signals, a neutral protective layer is then added to the carbon paths.

Materials for various applications

The researchers tested the process on various substrates, including PDMS (polydimethylsiloxane) – a soft form of silicon – agarose – a substance commonly used in biology experiments – and finally various forms of gelatin, including a gummy bear that was first melted and then allowed to harden. Each of these materials has properties suitable for certain applications. For example, gelatin-coated implants can reduce unwanted reactions in living tissue.

Through experiments with cell cultures, the team was able to confirm that the sensors provide reliable measurements. With an average width of 30 micrometers, they also permit measurements on a single cell or just a few cells. This is difficult to achieve with established printing methods.

"The difficulty is in fine-tuning all of the components – both the technical set-up of the printer and the composition of the ink," says Nouran Adly, the first author of the study. "In the case of PDMS, for example, we had to use a pre-treatment we developed just to get the ink to adhere to the surface."

Wide range of potential applications

Printed microelectrode arrays on soft materials could be used in many different areas. They are suitable not only for rapid prototyping in research, but could also change the way patients are treated. "In the future, similar soft structures could be used to monitor nerve or heart functions in the body, for example, or even serve as a pacemaker," says Prof. Wolfrum. At present he is working with his team to print more complex three-dimensional microelectrode arrays. They are also studying printable sensors that react selectively to chemical substances, and not only to voltage fluctuations.

Publication:

N. Adly, S. Weidlich, S. Seyock, F. Brings, A.Yakushenko, A. Offenhäusser, B. Wolfrum. “Printed Microelectrode Arrays on Soft Materials: From PDMS to Hydrogels.” Npj Flexible Electronics 2:1 (2018). DOI:10.1038/s41528-018-0027-z.

More information:

Prof. Wolfrum’s lab is part of the Munich School of BioEngineering (MSB). This interdisciplinary TUM research center is Europe’s most multi-disciplinary university institution focused on the interface between medicine, engineering and natural sciences.

Munich School of BioEngineering: https://www.bioengineering.tum.de/
Neuroelectronics Group: http://www.nel.ei.tum.de/

High resolution images:

https://mediatum.ub.tum.de/1446441

Contact:

Prof. Dr. Bernhard Wolfrum
Professor of Neuroelectronics
Munich School of BioEngineering
Department of Electrical and Computer Engineering
Technical University of Munich (TUM)
Tel.: +49 (89) 289 – 10887
bernhard.wolfrum@tum.de

Dr. Ulrich Marsch | Technische Universität München

More articles from Power and Electrical Engineering:

nachricht New discovery makes fast-charging, better performing lithium-ion batteries possible
16.04.2019 | Rensselaer Polytechnic Institute

nachricht SLAC develops novel compact antenna for communicating where radios fail
12.04.2019 | DOE/SLAC National Accelerator Laboratory

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: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

Im Focus: Largest, fastest array of microscopic 'traffic cops' for optical communications

The technology could revolutionize how information travels through data centers and artificial intelligence networks

Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...

Im Focus: A long-distance relationship in femtoseconds

Physicists observe how electron-hole pairs drift apart at ultrafast speed, but still remain strongly bound.

Modern electronics relies on ultrafast charge motion on ever shorter length scales. Physicists from Regensburg and Gothenburg have now succeeded in resolving a...

Im Focus: Researchers 3D print metamaterials with novel optical properties

Engineers create novel optical devices, including a moth eye-inspired omnidirectional microwave antenna

A team of engineers at Tufts University has developed a series of 3D printed metamaterials with unique microwave or optical properties that go beyond what is...

Im Focus: Newly discovered mechanism of plant hormone auxin acts the opposite way

Auxin accumulation at the inner bend of seedling leads to growth inhibition rather than stimulation as in other plant tissues.

Increased levels of the hormone auxin usually promote cell growth in various plant tissues. Chinese scientists together with researchers from the Institute of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

European Geosciences Union meeting: ExoMars press conference, live streams, on-site registration

02.04.2019 | Event News

 
Latest News

Light from exotic particle states

16.04.2019 | Physics and Astronomy

What happens in the bodies of ALS patients?

16.04.2019 | Life Sciences

Scanning for cancer treatment

16.04.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>