New Patents

Short-Pulsed Alkali Magnetometer for Precision in Ambient Fields

UW–Madison researchers have developed a method of spin polarization using an AC-coupled short pulse, permitting ultrasensitive magnetometry in the presence of Earth-level magnetic fields. By suppressing the spin-relaxation due to interactions between the instrument’s alkali atoms, the short pulses attain high transverse spin polarization free of dephasing collisions.

With increased sensitivity, the new design permits detection of minute fluctuations on par with other alkali-based magnetometers that require a near zero magnetic field environment.

The magnetometer includes a gas chamber exposable to an external magnetic field. An electromagnet is positioned to apply a local magnetic field to the chamber. By modulating the rotational change of the alkali atoms with a controllable time-dependent magnetic field, the atoms can be retained in a state in which collisions do not dephase their magnetic orientation.
(May 3, 2016) P110354US01

Producing Medical Isotopes with Dry-Phase Reactor

UW–Madison researchers have developed an improved method for generating medical isotopes using a dry-phase granular uranium compound, such as uranium salt or oxide.

In the process, the dry granular uranium is exposed to radiation that produces medical isotopes by nuclear reaction. The irradiated uranium then is dissolved in a solvent and the desired isotopes are extracted using standard aqueous separation techniques. The granular uranium material can be dried and reused.
(May 3, 2016) P120306US01

High-Resolution R2 Mapping with Chemical Species Separation

UW–Madison researchers have developed a method for producing a quantitative map of R2* while separating signal contributions from two or more chemical species, like fat and water.

The method works by producing quantitative R2* maps, quantitative fat fraction maps and separate R2*-corrected water and fat images. A low-resolution field map and a common water-fat phase are used to demodulate the effects of these parameters from the acquired data while separating the water and fat signals.

In this way, water, fat and R2* can be estimated simultaneously. A full resolution R2* map is reconstructed in addition to water, fat and fat fraction images that are corrected for the effects of R2*.
(May 3, 2016) P120316US01

New Mass Spectrometry Detector Uses Optically Active Membrane

UW–Madison researchers and collaborators have developed a mass spectrometry detector that is more sensitive to large molecule impacts and may provide better spatial sensitivity. The detector incorporates a thin membrane made of semiconducting materials. The membrane is optically active, converting the kinetic energy of the molecules that strike its front surface into light photons. The photons are detected and converted to an electrical signal by a photosensor.
(May 3, 2016) P140174US01

Manufacturing Polymer Micropellets

A UW–Madison researcher has developed a micropelletizing method and apparatus for controlling the size and shape of polymer particles.

In the process, a thin melt of polymer material is extruded through a specialized nozzle. A jet of heated, pressurized air then is applied. This causes the thread to stretch and break up into individual droplets due to surface tension effects known as Rayleigh disturbances.

The droplets are allowed to cool and solidify into micropellets. Factors like temperature, speed and extrusion rate are used to control droplet formation.
(Apr 26, 2016) P100314US02

Enzyme Aids Intranasal Drug Delivery

UW–Madison researchers have developed a method to enhance intranasal drug absorption using a naturally occurring endopeptidase, called matrix metalloproteinase-9 (MMP-9). This enzyme makes the nasal epithelium more permeable to drugs by degrading type IV collagen. Nasal spray or drops containing MMP-9 can be administered at the same time or prior to a drug to improve its absorption.
(Apr 26, 2016) P120322US02

DNA Sequencing with Piezoelectric Nanopore

UW–Madison researchers have developed a method for adjusting in situ the diameter of a nanopore used in a DNA sequencing device via piezoelectric tuning. The ability to control pore dimensions helps control the speed of the material passing through.

The substrate of the device is made of a piezoelectric material like quartz, which physically strains in response to an electric field. The substrate is positioned between reservoirs of conductive fluid and forms a nanoscale opening for DNA and ions. When an electrical signal is applied by a pair of electrodes on either side, the diameter of the opening changes due to piezoelectric shear strain. This constriction slows the passage of DNA through the pore long enough to identify one nucleotide at a time.
(Apr 26, 2016) P130036US01

Mobile Devices Conserve Energy by Adjusting Accuracy

A UW–Madison researcher has developed multiplication circuitry that dynamically changes its accuracy (and energy usage) in response to operating demands. Accuracy is adjusted to meet particular computation tasks, power management strategies or error thresholds.

Specifically, a shift and accumulate multiplication circuit precomputes multiplicand shift amounts rather than computing them on the fly with a ‘leading-one detector.’ The circuit prestores the values in a coefficient memory. A controller adjusts accuracy according to processor needs.

Precomputation is possible in many recognition tasks associated with HMIs, where relatively static multiplier coefficients are used.
(Apr 26, 2016) P130132US01

Memory Conserves Power, Is More Reliable

A UW–Madison researcher has developed a new memory structure (e.g., for caches, SRAM, DRAM, translation lookaside buffers, etc.) that controls error handling as a function of operating voltage. In this way, errors are corrected when the memory is run at low voltage and frequency.

The new design is made of multiple independently controlled groups of memory cells, each adapted to store digital data bits and error handling bits. A memory controller monitors the circuit to determine operating voltage and look for errors in the different groups when voltage is low. The groups have different physical sizes, and therefore have differing, predetermined susceptibility to errors as a function of voltage.

Performance issues associated with error correction, such as additional access latencies, can be avoided when the memory structure is run at a higher voltage (and frequency) and errors are less likely. Also, increased latencies due to evaluating error handling bits may be hidden by reading the digital data bits speculatively and assuming no errors.
(Apr 26, 2016) P140001US01

Bike Trailer Folds for Easy Storage

UW–Madison researchers have developed a new bicycle trailer design that stays attached while folding for easy storage. The trailer folds and pivots to align with the frame, allowing the user to store his/her bike effectively in a rack, apartment or tight space. The user can go from carrying a backpack, athletic bag or groceries to storing the entire bike/trailer setup in the same area the bike would occupy normally.

The trailer, which attaches to the fork rather than the axle, folds by pivoting up and forward to rest nearly on the seat, sides folded down. When folded it rests in a width thinner than the bike’s handlebars and extends only a few inches beyond the back tire.
(Apr 26, 2016) P140233US01