Jacob Sporrer

EECS Department, University of California, Berkeley

Technical Report No. UCB/EECS-2024-28

May 1, 2024

http://www2.eecs.berkeley.edu/Pubs/TechRpts/2024/EECS-2024-28.pdf

Intracortical recording devices have the capability to bring functionality back to people that have lost it through neurological conditions and injuries. These devices have been demonstrated in humans to control robotic limbs and enable brain-to-text communication. One major drawback of current intracortical recording technology is the limited effective recording lifetime of implant technology. To evaluate the lifetime of implants, durability studies are performed on implant designs. Current in vitro accelerated aging methods use heated saline baths intended to accelerate implant degradation using elevated temperatures and hydrogen peroxide to simulate the reactive oxygen attack that implants undergo as a part of the foreign body response. The focus of this thesis will be on the development of a microfluidic platform for durability evaluation of intracortical recording devices as well as a novel aging method that uses immune cells to simulate this reactive species attack. This work describes a microfluidic chamber design and fabrication process as well as techniques to control the reactive oxygen attack in the microreactor. The degradation of neural probes aged in microfluidic chambers using the saline/hydrogen peroxide method and the immune cell method is evaluated and compared to in vivo device degradation. An acceleration factor for immune cell aging is proposed for the acceleration of the reactive oxygen-induced polymer chain scission that occurs in vivo. Lastly, this work presents a model for implant lifetime prediction that incorporates both biological and material failure mechanisms using an equivalent circuit model for a neural implant.

Advisors: Vivek Subramanian

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BibTeX citation:

@phdthesis{Sporrer:EECS-2024-28,
    Author= {Sporrer, Jacob},
    Editor= {Subramanian, Vivek and Maharbiz, Michel and Arias, Ana Claudia and Healy, Kevin},
    Title= {Development of in vitro bioelectronic implant aging},
    School= {EECS Department, University of California, Berkeley},
    Year= {2024},
    Month= {May},
    Url= {http://www2.eecs.berkeley.edu/Pubs/TechRpts/2024/EECS-2024-28.html},
    Number= {UCB/EECS-2024-28},
    Abstract= {Intracortical recording devices have the capability to bring functionality back to people that 
have lost it through neurological conditions and injuries. These devices have been 
demonstrated in humans to control robotic limbs and enable brain-to-text communication. One 
major drawback of current intracortical recording technology is the limited effective recording 
lifetime of implant technology. To evaluate the lifetime of implants, durability studies are 
performed on implant designs. Current in vitro accelerated aging methods use heated saline 
baths intended to accelerate implant degradation using elevated temperatures and hydrogen 
peroxide to simulate the reactive oxygen attack that implants undergo as a part of the foreign 
body response. 
The focus of this thesis will be on the development of a microfluidic platform for durability 
evaluation of intracortical recording devices as well as a novel aging method that uses immune 
cells to simulate this reactive species attack. This work describes a microfluidic chamber design 
and fabrication process as well as techniques to control the reactive oxygen attack in the 
microreactor. The degradation of neural probes aged in microfluidic chambers using the 
saline/hydrogen peroxide method and the immune cell method is evaluated and compared to 
in vivo device degradation. An acceleration factor for immune cell aging is proposed for the 
acceleration of the reactive oxygen-induced polymer chain scission that occurs in vivo. Lastly, 
this work presents a model for implant lifetime prediction that incorporates both biological and 
material failure mechanisms using an equivalent circuit model for a neural implant.},
}

EndNote citation:

%0 Thesis
%A Sporrer, Jacob 
%E Subramanian, Vivek 
%E Maharbiz, Michel 
%E Arias, Ana Claudia 
%E Healy, Kevin 
%T Development of in vitro bioelectronic implant aging
%I EECS Department, University of California, Berkeley
%D 2024
%8 May 1
%@ UCB/EECS-2024-28
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/2024/EECS-2024-28.html
%F Sporrer:EECS-2024-28