Date of Graduation


Document Type


Degree Name

Bachelor of Science in Biomedical Engineering

Degree Level



Biomedical Engineering


Hestekin, Jamie


It is estimated that over 3 million cardiac pacemakers have been implanted in patients globally. Current lithium-iodine pacemaker batteries last an average of about 10 years before the entire pacemaker unit must surgically be replaced, increasing the patient’s risk of procedure-related complications. Therefore, it is necessary to investigate means by which to extend the pacemaker battery lifetime. The renal vein and renal artery in the body naturally produce a salinity gradient through the filtering work of the kidneys. This salinity gradient energy potential can be harnessed through reverse electrodialysis (RED). RED is an electrochemical process that harnesses the Gibbs Free Energy of Mixing between streams of different concentrations to generate power due to the movement of ions which is then converted into electrical current. Studies conducted at the University of Arkansas utilize a miniature RED “stack” composed of an ion exchange membrane, gaskets, flow spacers, and electrodes. This research aims to improve the RED device design by optimizing components and decreasing overall device size and to investigate the viability of a “salt chamber” device that adds additional ions to solution streams to increase solution differences and power output. Membrane area was increased and device thickness was decreased compared to the initial RED device design. Rudimentary ion transport experiment results indicated sufficient transport to warrant further investigation and design of a “salt chamber” device for further testing. Two different device designs were created and tested. The second “salt chamber” prototype device boosted increased hollow fiber membranes and active membrane area compared to the initial design. The second design also created a more static internal concentrate compartment, whereas the previous design included a concentrate compartment that was recycled with an external solution. This design allows for studies that will more closely mimic the actual device application and potential environment.


pacemaker battery, ion transport, salt chamber