Transparent MXene MicroECoG Electrodes for Multi-Modal Seizure Monitoring

Gari EberlyPhD students: Nicki Driscoll and Brendan Murphy

PI: Dr. Flavia VitaleCenter for Neuroengineering and Therapeutics

Epilepsy“Disorder of the brain characterized by the predisposition to

generate epileptic seizures”

[1] Epileptic seizures and epilepsy… Epilepsia, 46(4), 470-472.

Need to develop more effective treatments for epilepsy

Need to develop more effective treatments for epilepsy

Development requires characterization of behavior and pathway of seizure

Need to develop more effective treatments for epilepsy

Development requires characterization of behavior and pathway of seizure

Must monitor seizure on micron level with high temporal and spatial resolution

Develop a micro-electrocorticographic device capable of multi-modal seizure monitoring

Two-Photon Imaging

Electrophysiological Recording

Develop a micro-electrocorticographic device capable of multi-modal seizure monitoring

[2] Transparent and flexible low noise graphene electrodes for simultaneous electrophysiology and neuroimaging. Nature communications, 5, 5259.

Develop a micro-electrocorticographic device capable of multi-modal seizure monitoring

[3] Epidural and foramen-ovale electrodes in the diagnostic evaluation of patients considered for epilepsy surgery. Epileptic disorders : international epilepsy journal with videotape. 12. 48-53.

MXene (Ti3C2Tx)

✓Sheet resistance(47 Ω/sq at 62 nm)

✓Volumetric Capacitance(676 F cm−3)

✓Conductivity(10,000 S/m)

✓Biocompatible✓Flexible✓Hydrophilic

[4] High-Capacitance Mechanism for Ti3C2Tx MXene by in Situ Electrochemical RamanSpectroscopy Investigation. ACS nano, 10 12, 11344-11350 .

Fabrication and CharacterizationUse MXene to create transparent Micro-ECoG electrodes

Optimize spray coating procedure

Characterize MXene electrodes using electrochemical impedance spectroscopy and UV-Vis spectroscopy

1 2

Si Parylene-C Gold MXene SiO2 Al

2 3

Si Parylene-C Gold MXene SiO2 Al

3 4

Si Parylene-C Gold MXene SiO2 Al

4 5

Si Parylene-C Gold MXene SiO2 Al

5 6

Si Parylene-C Gold MXene SiO2 Al

6 7

Si Parylene-C Gold MXene SiO2 Al

8

Final8

Gold Pads

MXene Traces

Parylene-C Encapsulation

1.5 mm

Device CharacterizationObserved optical transparency and film quality

UV-Vis Spectroscopy - more precisely characterize transparency of Ti3C2Tx films at wavelengths ranging from 340-1000 nm

Electrochemical impedance spectroscopy (EIS) - characterize impedanceof the Ti3C2Tx electrodes.

Bright Field Microscopy

Graphene 10 - MXene 5 - MXene 15 - MXene

UV –Vis Spectroscopy

Transmittance at 550 nm:

5 Sprays: 74 ± 1%

10 Sprays: 68.2 ± .8%

15 Sprays: 44.2 ± .5%

Common λ - Two-Photon Imaging

EIS

Impedance at 1 kHz:

5 Sprays: 280 ± 73 kΩ

10 Sprays: 46 ± 14 kΩ

15 Sprays: 5 ± 1 kΩ

Graphene: 2110 ± 98 kΩ

Graphene 10 - MXene

5 - MXene 15 - MXene

Thank you!!REU Students: Tessa Posey, Nancy Rodriguez Mentors: Nicki Driscoll, Brendan Murphy, Dr. Nick ApolloPIs: Dr. Flavia Vitale and Dr. Brian LittCNT: Carolyn Wilkinson, Everett PrinceSingh REU: Kristin Field, Eric Johnson

Transparent MXene MicroECoG Electrodes for Multi-Modal Seizure Monitoring

Gari EberlyPhD students: Nicki Driscoll and Brendan Murphy

PI: Dr. Flavia VitaleCenter for Neuroengineering and Therapeutics