2D metal carbides and nitrides (MXenes) electrodes

Problem:

Current implantable devices for recording and stimulating electrical activity in the body are fabricated with metal based components. The metal components pose issues for long term implantation and functionality, including scarring, inflammation, degradation and fatigue. Furthermore, the physical properties of metals are typically inadequate to achieve good quality recording and stimulation performance.

Solution:

MXene’s offer a unique combination of electrical conductivity, strength, flexibility and volumetric capacitance (300-400 F/cm3). Furthermore, by varying processing parameters, the MXenes are >90% transparent. The electrochemical impedance of MXene neural sensors measured at 1 kHz is 4 times smaller than that of gold electrodes of the same size. When used for recording of neural signal in vivo, this reduction in impedance significantly suppresses noise from electrical interference (> 400-fold reduction compared to gold electrodes) and from electronic noise in the electrode itself (50% less than gold).

The MXene ECoG electrodes were tested in vivo in an anesthetized rat, where they were placed on the exposed cortex, showing significantly reduced baseline noise compared to gold electrodes of the same size. Excitingly, penetrating MXene depth electrodes recorded unit activity (individual neuron spiking activity), which was not detected on the gold contacts. (Fig.1A & 1B).

Applications:

• $1,054 million (2015) Global Medical Electrodes Market, reaching $1,328 million by 2022
• Clinical applications in neurodegenerative disease; epilepsy and cardiovascular disorders including as Pacemaker electrodes (Cardiovascular), DBS electrodes (ie. Parkinson’s Disease), BMI electrodes, intracranial EEG electrodes, and penetrating intracortic electrode arrays.
• Transparent biological sensors for imaging and intracellular recordings.

Advantages:

• Significant suppression of electrical interference and electronic noise in the electrode.
• Better electrical conductivity, strength, flexibility and volumetric capacitance.
• Better optical properties than metals including tunable optical transparency (>90 %)
• Unique ability to record single unit neuron activity.

Stage of Development:

• Fabrication of two types of electrodes for measuring ECoG and individual neurons
• Characterization of electrochemical impedance
• Enhanced performance during in vivo testing

Intellectual Property:

• US 11,925,466 

Reference Media:

• Anasori, Be. et al.;  Nature Reviews Materials, 2: 16098

Docket # 17-8285