STTR Phase I: Ferrofluidic enclosures for enhanced control of thermal and magnetic fields in spin-stabilized atomic micro-devices

The broader impact/commercial potential of this project is determined by new consumer products and new industries which would flourish on portable and reliable atomic clocks, gyroscopes, and magnetometers when they become available. Proposed compact thermal and magnetic enclosure reduces the most bulky part of such devices and provides an avenue for further miniaturization. A chip-scale atomic clocks would dramatically increase GPS resolution and relocking speed, computer clocks and broadband speed, better use of electromagnetic spectrum for communication and networking devices. Examples of inertia navigation applications with significant society impact include urban conditions, underwater or mountain terrain, building interior or underground facilities, areas with poor satellite reception or jammed signal. A typical reference source for recalibration of inertia navigational systems is the magnetometer measurements. In addition high resolution portable magnetometers would be essential in cars/highway safety, in industrial applications for material sorting and handling, quality control, and nondestructive defectoscopy. Bio-magnetic studies such as magnetic orientation of vertebrates (animal/birds/fish) and bacteria could bring many insights for human navigation as well. Biomedical diagnosis often uses magnetic measurements: this includes NMR scanning, study of brain electro-activity, blood cell counting, and DNA markers. This Small Business Technology Transfer (STTR) Phase I project targets a micro-enclosure controlling temperature and magnetic field in chip-scale Nuclear Magnetic Resonance (NMR) devices. Precise control of the temperature and the magnetic field inside the camber containing vapor of alkali-metal atoms is critical for performance of NMR devices; however, current approaches depend on a bulky equipment which is far from being portable. A novelty of the proposed design is linking MNR chamber, heating elements, thermal sensor and solenoid coils by a ferrofluidic enclosure. High magnetic permeability of ferrofluid reduces the number of coils and the current density, required to produce the desired magnetic field and assists in providing highly uniform and controllable magnetic field in the micro-enclosure; in addition, ferrofluid operates as a heat reservoir keeping uniform and stable temperature regime. Ferrofluid could also self-sense a temperature change in the chamber without involving additional thermal sensors, thus simplifying the device construction and reducing its cost. The proposed activity includes development, prototyping and testing performance of the enclosure. Further development in Phase II would include coupling of the enclosure with a portable NMR chamber. Eventually, a similar approach will be applied for magnetic coupling with microfluidic sampling and probing stations for bio-magnetic studies.