New Patents

Superior Plastic Parts

UW–Madison researchers have developed a new method to create foamed, injection-molded plastic blends with significantly increased toughness and ductility compared to conventional foamed parts.

The new process begins with a polymer blend with two properly selected polymer materials, such as polypropylene (PP) and high-density polyethylene (HDPE), or PP and low-density polyethylene (LDPE), which exhibit a dispersed secondary phase at sub-microscale in the primary matrix. The polymer blend is heated along with a supercritical fluid in an extruder to produce a melt, which is then extruded into gas-laden pellets. The gas-laden pellets can be fed into the injection barrel of a typical machine, plasticized and then injected into a mold cavity (or cavities) where the final part is made.

The process forms a lightweight component with microscale air cavities. Upon tensile loading, debonding of the secondary phase facilitates the interconnection of microcellular voids to form channels such that the stretched component becomes a bundle of fibrils. Compared to other toughening methods, this method achieves a more significant improvement in ductility and toughness. It also has the benefit of higher production efficiency, better dimensional stability, and greater design freedom thanks to the foamed injection molding process.
(Jan 31, 2017) P140042US01

Sustainable Organic Aerogels for Insulation

UW–Madison researchers have developed hybrid organic aerogels with desirable insulation properties. They are made by combining a water soluble polymer and a carbon nanofiller such as graphene oxide nanosheet with cellulose nanofibrilliated fibers (CNFs) derived from biomass. The organic polymer, such as polyvinyl alcohol (PVA), is cross-linked to form a gel and water is removed by freeze-drying. The surface of the aerogel can by further modified.
(Jan 24, 2017) P120283US03

Solar Cells Track Sun

UW–Madison researchers have developed a passive solar tracking system utilizing materials that move in response to sunlight.

In the system, a solar cell panel is supported by flexible posts. The posts are made from a composite material, including a liquid crystal elastomer. This material has properties that cause it to contract and tilt when exposed to heat. To further exploit such properties, the material is embedded with carbon nanotubes that act as miniature heat sources, absorbing sunlight and giving off warmth.
(Jan 17, 2017) P120269US01

More Efficient Processing with Self-Invalidating IOMMU Mapping

UW–Madison researchers have developed a more efficient IOMMU. They recognized that the time required to delete a page table entry (PTE) from the page table and send the IOMMU cache deletion signal can be eliminated for most transactions.

This is done by attaching a ‘removal rule’ to the PTE that allows for self-deletion. The removal rule may, for example, delete the PTE after a predetermined number of memory accesses or a specified time. This significantly cuts processor time and resources required for IOMMU transactions. Also, the susceptibility of the computer to I/O device or driver errors is reduced.
(Jan 17, 2017) P140029US01

Voltage Regulator Control for Processors Conserves Energy

A UW–Madison researcher has developed an improved VR system for next-generation hardware providing direct rather than inferred current measurements. In the new system, a controller manages the number of active phases of each VR according to a determined electrical current demand from the processor.

Relying on electrical current demand (rather than P-state) boosts VR efficiency, particularly in situations where low current demand occurs under heavy processor demand because of certain power variations.
(Jan 17, 2017) P140423US01

Ultra-Efficient Continuous Monitoring of Sensors

UW–Madison researchers have developed reconfigurable event-driven hardware that enables low-power continuous monitoring by offloading tasks from the primary processor.

The hardware interfaces with sensors and invokes the processor only when a trigger signature is detected. It can be implemented as a separate integrated chip or as a low-power compute resource within the primary processor.
(Jan 10, 2017) P130049US01

Pourable Ceramic Core Recipe For Direct Pattern Contact

Researchers at the University of Wisconsin – Whitewater and collaborators have developed a new high viscosity refractory material that forms a ready-to-pour ceramic core in as little as 30 minutes. This newly developed core material has the advantage of being able to cure quickly without generating a strong exothermic reaction upon curing. The low curing temperatures allow the new core material to be poured directly into the deep cavities of a pattern without causing pattern surface deformation. The new refractory core material greatly decreases the time from coating pattern to pour as the material can be exposed to temperatures up to 3,200 degrees fahrenheit after 30 minutes of curing at room temperature. In addition, the refractory bonds well with traditional investment casting shell materials. When high temperatures are applied during the casting process the strength of the refractory material is reduced, thereby enhancing the ability to remove the investment casting material from the cast product while still accurately reproducing fine details of the pattern. Shell removal can be accomplished with high pressure water as opposed to hammering or the use of abrasives, creating a lower impact process of removal.
(Jan 10, 2017) T120015US03

Modular Investment Casting Mold Assembly

Traditional ceramic investment casting requires that patterns duplicating the desired finished product are attached directly to a wax or plastic sprue. Multiple patterns may be attached to a sprue creating an inverted tree-like structure. The pattern-sprue assembly is then encased in a ceramic mold material or refractory. The refractory containing the wax pattern-sprue assembly is then heated to melt and burn off the wax pattern and sprue in order to create a cavity in which molten metal can be poured. Volatilized hydrocarbon wax released during burnout is a major cause of pollution from investment casting foundries and wax is a major expense for foundries. There is an opportunity to markedly reduce wax usage, reduce pollution from the casting process and centralize sprue creation by making a prefabricated, modular, ceramic sprue. The wax pattern material is melted/burned off from the individual shells before they are attached to the prefabricated sprue. If a pattern breaks before it is cast, this technology allows for the broken pattern to be replaced without needing to recreate the entire sprue assembly.This reduces the amount of pattern material needed to create an end product. It also permits the use of less expensive and less precise refractory material for the prefabricated sprue than is used to coat the patterns. The technology will allow foundries to reduce infrastructure associated with traditional sprue creation and will allow for centralized production of modular sprues to decrease duplicative work within each foundry.
(Jan 10, 2017) T120016US02

Microcavity Method for Single Molecule Spectroscopy

Specifically, the researchers have developed a new microcavity-based method for single molecule/particle spectroscopy. In essence, when an individual molecule or particle lands on the microcavity surface, it absorbs energy from a free space pump laser beam and generates heat. The heat is transferred to the microcavity, causing a shift in resonance frequency and therefore detectable changes in the light (e.g., power or intensity).

The superb sensitivity of the method enables detection, identification and real-time analysis of single molecules and particles. This is exciting because current spectroscopy techniques are limited to matter in the 10 to 100 nanometer size range, such as nanoparticles and viruses.
(Jan 3, 2017) P140153US03

Eardrum Nanomembrane Offers Tinnitus Care

UW–Madison researchers have developed a flexible membrane that attaches to the eardrum and detects vibrations. Alternatively, it can be signaled to excite the eardrum.

The nano-thin membrane is made of piezoelectric material. This type of material generates electricity in response to motion, or the reverse, generating motion in response to electricity.

Given this phenomenon, the membrane can be coupled to an antenna and electrodes to act as a transducer, transforming one form of energy into another. Thus, when sound waves strike the eardrum, the shaken membrane produces electrical energy that may be sent out and detected by a transceiver. Conversely, an ingoing radio frequency signal can be received by the electrodes and passed on as audio stimulation to the membrane, causing it to vibrate.
(Dec 27, 2016) P120327US01