Magnetic Field Sensors
TIPD, LLC has developed a field-deployable, highly sensitive, packaged, low cost, gradient magnetometer, capable of operating under ambient conditions at room temperature. The magnetometer employs an ultra-high Verdet constant magneto-optic (MO) nanoparticle film to deliver a high dynamic range magnetic field gradient measurement system for no ninvasive, real-time monitoring of bio-magnetic activities with high spatiotem poral resolution in an unshielded environment. Each gradient measurement system will consist of one scalar magnetic field sensor, one each of horizontal and vertical gradiometers, and an additional scalar magnetic field sensor for background magnetic field measurement and cancellation. The entire sensor assembly can fit in less than 1cc volume and would weigh only a few grams. A prototype sensor, developed under a DARPA Phase 1 SBIR is based on fiber optic in-line Sagnac interferometers and auto balanced detectors fornoise cancellation. The prototype successfully demonstrated a noise equivalent sensitivity (NES) of ~10 fT/cm/ √ Hz in an unshielded environment, enabling measurements of extremely small magnetic fields in unshielded environments.
The gradiometer system has both military and civilian applications. The military applications include: (a) magnetic anomaly detection, (b) anti-submarine warfare, (c) unexploded ordnance detection, and (d) through-wall imaging. Civilian applications include: (e) dynamic imaging of biological processes for biomedical research and clinical diagnosis, including magnetoencephalography (MEG), magnetocardiography (MCG), fetal magnetocardiography (fMCG) and monitoring the peripheral nervous system (PNS); (f) spinal signal detection, diagnosis of mild traumatic brain injury (mTBI), and accelerating the development of brain-machine interfaces (BMI), and (g) noninvasive brain imaging in real time to enable researchers to identify neural networks involved in cognitive processes, understand disease pathways, recognize and diagnose diseases early, when they are most effectively treated; and determine how therapies work.