Cerebral spinal fluid (CSF) shunting is a long-term treatment option for hydrocephalus, a congenital condition associated with accumulation of cerebral-spinal fluid in the brain. If left untreated, hydrocephalus leads to developmental disabilities and death. Implanted cerebrospinal fluid shunts have been in use since the 1950's; however approximately 39% of shunts fail within the first year, 53% fail within the first two years, and about 80% fail at some point after implantation. The goal of this research project is to develop a "smart" CSF flow sensor, capable of reporting the amount of CSF drained from the brain after implantation. The proposed solution is based on the combined use of ultra-sensitive magnetoresistance sensors, radio-frequency identification technology, and advances in the manufacturing of super paramagnetic micro-structures. This research is expected to significantly improve the quality of life of individuals with hydrocephalus, as pending shunt failure can be detected early to allow correction before adverse health or cognitive effects occur. The research team also plans to integrate this research into undergraduate and graduate educational activities and, based on a common goal of developing low cost medical sensors, develop an undergraduate design program that integrates business practices into the design process to improve the likelihood of successful application of the designed systems. The scientific objective of this proposal is to demonstrate the feasibility of using giant magneto-resistance sensors in the detection of very slow-moving fluids, such as cerebral spinal fluid. The latest generation of these sensors, known as magneto tunneling junction devices, will be used to detect flow-induced motion of a cilia-like structure inside the lumen of a ventriculoperitoneal shunt. Realization of such non-contact measurements requires new sensor architectures immune to low-frequency noise (sensor drift), rejection of ambient magnetic interference, and development of an ultra-low power sensor interrogation scheme allowing for wireless operation. The present effort will investigate the low-frequency noise sources in MTJ sensors, indirect methods for re-calibration of the sensor, and will develop an inductively powered flow sensor capable of resolving CSF flow with 1mL/hr resolution. The knowledge gained will be applicable not only to hydrocephalus shunts, but to measurement of low-flow volume systems more generally. In addition, it is expected that there will be a significant advancement in knowledge regarding magneto tunneling junction devices themselves.