Flexible Multielectrode Arrays With 2-D and 3-D Contacts for In Vivo Electromyography Recording

Area of Science:

• Neuroscience
• Bioengineering
• Animal Behavior

Background:

• Understanding neural control of motor behaviors requires precise measurement of muscle activity.
• Electromyography (EMG) is crucial for studying motor control but requires advanced recording techniques for high-fidelity signals.
• Songbirds offer a valuable model for studying complex motor control, including vocalization and respiration.

Purpose of the Study:

• To develop and evaluate novel flexible multielectrode arrays (MEAs) for in vivo EMG recordings in songbirds.
• To compare the performance of 2-D and 3-D MEAs in terms of signal quality and biocompatibility.
• To investigate the neural control of breathing and motor behaviors through simultaneous EMG and air pressure measurements.

Main Methods:

• Fabrication of hybrid polyimide-polydimethylsiloxane (PDMS) flexible MEAs with varying 2-D electrode dimensions and pitches.
• Development of 3-D MEAs using a photoresist reflow process for hemispherical electrode domes.
• In vivo recording of EMG signals from songbird expiratory muscles and simultaneous air pressure measurements from air sacs.

Main Results:

• Successfully recorded in vivo EMG signals from songbirds using both 2-D and 3-D flexible MEAs.
• Demonstrated biocompatibility and flexibility of the polyimide-PDMS hybrid arrays.
• Achieved a significant improvement of over 7-fold in signal-to-noise ratio (SNR) with 3-D MEAs compared to 2-D MEAs.

Conclusions:

• The developed hybrid flexible MEAs, particularly the 3-D configuration, are effective for high-quality in vivo EMG recordings in songbirds.
• Simultaneous EMG and air pressure recordings provide insights into the neural control of breathing and motor behaviors.
• This technology holds potential for advancing motor control research across various species, including humans.