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Graphene and gold make a better brain probe

  • 조회. 998
  • 등록일. 2017.04.19
  • 작성자. Administrator

Graphene and gold

make a better brain probe











A team from Korea

created more flexible neural electrodes that minimize tissue damage and still

transmit clear brain signals.



 



Electrodes placed

in the brain record neural activity, and can help treat neural diseases like

Parkinson’s and epilepsy. Interest is also growing in developing better

brain–machine interfaces, in which electrodes can help control prosthetic

limbs. Progress in these fields is hindered by limitations in electrodes, which

are relatively stiff and can damage soft brain tissue.



 



Designing

smaller, gentler electrodes that still pick up brain signals is a challenge

because brain signals are so weak. Typically, the smaller the electrode, the

harder it is to detect a signal. However, a team from the Daegu Gyeongbuk

Institute of Science & Technology in Korea developed new probes that are

small, flexible and read brain signals clearly.



 



The probe

consists of an electrode, which records the brain signal. The signal travels

down an interconnection line to a connector, which transfers the signal to

machines measuring and analysing the signals.



 



The electrode

starts with a thin gold base. Attached to the base are tiny zinc oxide nanowires,

which are coated in a thin layer of gold, and then a layer of conducting

polymer called PEDOT. These combined materials increase the probe’s effective

surface area, conducting properties, and strength of the electrode, while still

maintaining flexibility and compatibility with soft tissue.



 



Packing several

long, thin nanowires together onto one probe enables the scientists to make a

smaller electrode that retains the same effective surface area of a larger,

flat electrode. This means the electrode can shrink, but not reduce signal

detection. The interconnection line is made of a mix of graphene and gold.

Graphene is flexible and gold is an excellent conductor. The researchers tested

the probe and found it read rat brain signals very clearly, much better than a

standard flat, gold electrode.



 



"Our graphene and

nanowires-based flexible electrode array can be useful for monitoring and

recording the functions of the nervous system, or to deliver electrical signals

to the brain," the researchers conclude in their paper recently published in

the journal ACS
Applied Materials and Interfaces.



 



The probe

requires further clinical tests before widespread commercialization. The

researchers are also interested in developing a wireless version to make it

more convenient for a variety of applications. 






Journal Reference  






Enhancement of Interface Characteristics of Neural Probe Based on Graphene, ZnO Nanowires, and Conducting Polymer PEDOT






Abstract 



In the growing field of brain–machine interface (BMI), the interface between electrodes and neural tissues plays an important role in the recording and stimulation of neural signals. To minimize tissue damage while retaining high sensitivity, a flexible and a smaller electrode with low impedance is required. However, it is a major challenge to reduce electrode size while retaining the conductive characteristics of the electrode. In addition, the mechanical mismatch between stiff electrodes and soft tissues creates damaging reactive tissue responses. Here, we demonstrate a neural probe structure based on graphene, ZnO nanowires, and conducting polymer that provides flexibility and low impedance performance. A hybrid Au and graphene structure was utilized to achieve both flexibility and good conductivity. Using ZnO nanowires to increase the effective surface area drastically decreased the impedance value and enhanced the signal-to-noise ratio (SNR). A poly[3,4-ethylenedioxythiophene] (PEDOT) coating on the neural probe improved the electrical characteristics of the electrode while providing better biocompatibility. In vivo neural signal recordings showed that our neural probe can detect clearer signals.






[DGIST Research News in Media] 



●[ScienceDaily] Graphene and gold make a better brain probe



[Nanowerk] Graphene and gold make a better brain probe



[Scienmag] Graphene and gold make a better brain probe



[Oandp.com] Graphene and Gold Make a Better Brain Probe



[NewsCaf] Graphene and gold make a better brain probe