As scientists learn more about disease pathologies and treat various medical conditions, the need to develop new tools grows rapidly. Multifunctional polymer fibers allow scientists to have a plethora of tools by fine tuning parameters to create affordable, unique, and adaptable devices for analyte sensing and disease treatment. The range of applications mutltifunctional fibers have in biomedical applications can be seen with sensing in wearable electronics or in neural probes due to their ability to easily integrate microfluidic systems, electrical, and optical means of sensing and stimulating. This thesis will demonstrate several ways fiber devices can be used in biomedicine and show the future direction of fiber based devices. / Master of Science / Everyday scientists face new challenges and seek to understand new aspects of many medical conditions in the effort to cure or treat diseases. The common goal of improving the quality of life people face prompts the need for innovative, individualized, and minimized systems for treating medical conditions. Whether the condition involves sensing sweat to maintain glucose levels, extracting small tumorous tissue in sensitive areas, or detecting seizures before they happen, multifunctional fiber devices show a promising future for many biomedical device needs. Their ability to be easily made in a quantity of hundreds of meters at a time, combined with their tunable parameters, allow for them to be used and catered to many different applications. This thesis demonstrates several ways fiber devices have been used and what areas they can expand into as the field progresses.