University of Pittsburgh researchers have developed a novel method to monitor alternating electric currents and magnetic fields of up to 15 kHz. Using a magnetic nanoparticles-based sensor that can be used in either the liquid or solid phase, this technology may have a wide variety of applications including broader band optical communications.
Description
Optical sensing is used in many sectors to measure everything from biomedical information to high-speed communications. Existing sensors are based on multimode interferometry (MMI) architecture. In this novel sensing approach, a sensor is fabricated by fusion splicing a multi-mode fiber (MMF) with stripped cladding enclosing a magnetic fluid (ferrofluid) or a no-core fiber (NCF) section to single-mode fibers (SMF). The inclusion of ferrofluid in this technology can enhance the detected signal. This magnetic fluid (MF) sensor could lead to faster telecommunications and revolutionize the optical sensor industry.
Applications
• Space and navigation
• Monitoring current anomalies in power grids
• Quantum computing
Advantages
Ferrofluids are permanently magnetized single-domain nanoparticles of ferromagnetic materials, usually magnetite (Fe3O4) and maghemite (-Fe3O4) in a non-magnetic carrier liquid and a thin layer coating of surfactant. The dynamic response of ferrofluids to high-frequency AC-currents (MHz to GHz range) has been well established. However, the application of magnetic fluids as sensing materials in various fiber-optic sensors has not been explored in depth.
With a need to develop optical sensors capable of working at broader bandwidth, ferrofluids offer the potential to produce low-cost, tunable novel optical sensors. The properties of ferrofluids can be modified by changing the concentration of magnetic nanoparticles and it is predicted that these novel sensors’ frequency response could be pushed to higher frequencies than are currently available. Such improvements can expand optical sensing capabilities of electric currents and magnetic fields across industries.
Invention Readiness
A prototype MF sensor has been developed and experiments found this sensor could detect AC-current frequencies of up to 15 kHz with a sub-millisecond dynamic response time. Testing has confirmed this sensor can accurately monitor AC-current in power lines and detect current fault profiles based on changes in the magnetic field. This MF sensor is optimized for fourth self-imaging and can be interrogated at the telecommunications C-band wavelength (1530-1565 nm).
IP Status
Patent pending
