2 research outputs found
Fluidic Microactuation of Flexible Electrodes for Neural Recording
Soft
and conductive nanomaterials like carbon nanotubes, graphene,
and nanowire scaffolds have expanded the family of ultraflexible microelectrodes
that can bend and flex with the natural movement of the brain, reduce
the inflammatory response, and improve the stability of long-term
neural recordings. However, current methods to implant these highly
flexible electrodes rely on temporary stiffening agents that temporarily
increase the electrode size and stiffness thus aggravating neural
damage during implantation, which can lead to cell loss and glial
activation that persists even after the stiffening agents are removed
or dissolve. A method to deliver thin, ultraflexible electrodes deep
into neural tissue without increasing the stiffness or size of the
electrodes will enable minimally invasive electrical recordings from
within the brain. Here we show that specially designed microfluidic
devices can apply a tension force to ultraflexible electrodes that
prevents buckling without increasing the thickness or stiffness of
the electrode during implantation. Additionally, these “fluidic
microdrives” allow us to precisely actuate the electrode position
with micron-scale accuracy. To demonstrate the efficacy of our fluidic
microdrives, we used them to actuate highly flexible carbon nanotube
fiber (CNTf) microelectrodes for electrophysiology. We used this approach
in three proof-of-concept experiments. First, we recorded compound
action potentials in a soft model organism, the small cnidarian <i>Hydra</i>. Second, we targeted electrodes precisely to the thalamic
reticular nucleus in brain slices and recorded spontaneous and optogenetically
evoked extracellular action potentials. Finally, we inserted electrodes
more than 4 mm deep into the brain of rats and detected spontaneous
individual unit activity in both cortical and subcortical regions.
Compared to syringe injection, fluidic microdrives do not penetrate
the brain and prevent changes in intracranial pressure by diverting
fluid away from the implantation site during insertion and actuation.
Overall, the fluidic microdrive technology provides a robust new method
to implant and actuate ultraflexible neural electrodes
Fluidic Microactuation of Flexible Electrodes for Neural Recording
Soft
and conductive nanomaterials like carbon nanotubes, graphene,
and nanowire scaffolds have expanded the family of ultraflexible microelectrodes
that can bend and flex with the natural movement of the brain, reduce
the inflammatory response, and improve the stability of long-term
neural recordings. However, current methods to implant these highly
flexible electrodes rely on temporary stiffening agents that temporarily
increase the electrode size and stiffness thus aggravating neural
damage during implantation, which can lead to cell loss and glial
activation that persists even after the stiffening agents are removed
or dissolve. A method to deliver thin, ultraflexible electrodes deep
into neural tissue without increasing the stiffness or size of the
electrodes will enable minimally invasive electrical recordings from
within the brain. Here we show that specially designed microfluidic
devices can apply a tension force to ultraflexible electrodes that
prevents buckling without increasing the thickness or stiffness of
the electrode during implantation. Additionally, these “fluidic
microdrives” allow us to precisely actuate the electrode position
with micron-scale accuracy. To demonstrate the efficacy of our fluidic
microdrives, we used them to actuate highly flexible carbon nanotube
fiber (CNTf) microelectrodes for electrophysiology. We used this approach
in three proof-of-concept experiments. First, we recorded compound
action potentials in a soft model organism, the small cnidarian <i>Hydra</i>. Second, we targeted electrodes precisely to the thalamic
reticular nucleus in brain slices and recorded spontaneous and optogenetically
evoked extracellular action potentials. Finally, we inserted electrodes
more than 4 mm deep into the brain of rats and detected spontaneous
individual unit activity in both cortical and subcortical regions.
Compared to syringe injection, fluidic microdrives do not penetrate
the brain and prevent changes in intracranial pressure by diverting
fluid away from the implantation site during insertion and actuation.
Overall, the fluidic microdrive technology provides a robust new method
to implant and actuate ultraflexible neural electrodes