Covering All Technology and Application Areas of Additive Fabrication Including:
RAPID PROTOTYPING    3D PRINTING    RAPID TOOLING    RAPID MANUFACTURING

Update 59.      BRIEF Highlights 6/9/09 to 9/8/09:

A horse-choking 229 US RP patents and patent applications were published during this three month period. It's estimated that the original material reviewed for this update is aproximately 5,700 pages. Obviously, this summary can't provide a complete picture of all important developments. A detailed analysis, with complete information about each patent and application published during the period is available at low cost. This indexed, Acrobat pdf format report is more than 200 pages long and includes more than 200 illustrations. Review the entire contents rapidly by category, or quickly page through to make sure you know what's happening in the complex world of Additive Fabrication technology. Here are a FEW highlights from Update 59.

ISSUED PATENTS and PATENT APPLICATIONS PUBLISHED

Technology

• The University of Texas has been granted a patent for multi-material stereolithography. The machine configuration uses a straightforward arrangement of multiple vats and various means of moving a part amongst them. A related patent application from the same group combining other technologies with stereolithography was also published this quarter.

• If the technology described in a patent issued to Lockheed Martin Corp. is ever reduced to practice, it may be well be the Holy Grail of additive fabrication. A hologram is projected into a liquid, gaseous or other medium which it solidifies in three dimensions. Holographic movies could be used to create very complicated objects. See Fig. 1.

• Stratasys Inc. has applied for three patents on the use of embedded inserts such as RFID tags for part tracking. One of the applications shows a method of combining robotic insertion of the tags with the fused deposition modeling process.

• United Technologies Corp. has applied for a patent on what it terms a solid state additive manufacturing system. The method uses a rotating material feed rod held against a substrate to produce frictional heat to melt the material. The process is very much like friction stir welding and is said to overcome problems with melt pool-based technologies especially the ability to deposit fine grain materials. See Fig. 2.

 

• United Technologies Corp. also has applied for a patent concerning the use of additive fabrication to make turbine disks from multiple materials in order to minimize both centrifugal and thermal stresses. The parts may, for example, be used in auxiliary power units which are run from gas turbine engines. See Fig. 3.

• The Aerospace Corp. describes a radial flow solid fuel rocket motor made by stereolithography or other three dimensional printing process in its just-published patent application. The method provides a complex gas flow path and improved oxidizer/fuel ratio throughout the burn while offering better support for the fuel. See Fig. 4.

• Inventor Quang-Viet Nguyen has received a patent for a compact and rugged imaging Raman spectrograph. Stereolithography or other 3D printing processes may be used to make the complex device as a single unit, allowing its use in portable chemical analysis applications.

• Gowland and Longfield (UK) have applied for a patent on a means of shimming magnetic coils for MRI and similar equipment. The technique is said to result in improved uniformity of the magnetic field and simplified manufacture.

• SAAB AB (Sweden) has applied for a patent on a warhead casing. Fabricated using aluminum filled nylon laser sintering materials, the case is claimed to provide better vibration, heat-resistance and other characteristics as well as to avoid collateral damage exposure.

  

• The Boeing Company's patent application for a high density structural health monitoring system obviously applies to aircraft structures, but it could have many other applications as well for buildings, bridges and perhaps even individual small parts in critical applications. A piezoelectric actuator and a sensor are fabricated in close proximity to each other within or upon the structural element to be monitored by additive techniques. Changes in the resonant frequency of the system may be interpreted as changes in the structure. Years ago this was basically the way railway train wheels were inspected. A "car knocker" would prowl about the rail yard hitting each wheel with a hammer. When a wheel didn't sound right, the car was taken out of service. See Fig. 5.

• A potentially significant use to which additive fabrication brings considerable advantage is described in a patent application by Jason Moore. Laser sintering is used to manufacture the complex core of a valve for controlling high pressure and high speed fluid flows such as steam, oil, gas or paper pulp. The design of the valve could obviously be adjusted to provide various turn-on or turn-off features. See Fig. 6.

• The use of graded-materials can have some non-obvious, but nevertheless significant applications. One of these is the subject of a patent application by Lehigh University. It concerns a transition joint as a welding aid to help join the mild steel of boiler tubes to the high performance steel used in superheaters. There could be many such applications in industry.

• The US Navy has applied for a patent to extend its Laser Induced Forward Transfer (LIFT) technology. The technique described can be used to transfer entire chip-level and surface-mount devices according to the authors. The components may be laser-transferred into laser-cut pockets, then interconnected by laser direct writing techniques to create fully-functional circuits.

• Technische Universitat Wien (Austria) has applied for a patent on photopolymer materials that can be dissolved in an organic solvent. This permits using stereolithography to fabricate molds for parts that may be sensitive to water.

• In Technology Holdings LLC has received a patent for hydrodynamic multi-focal contact lenses made by jetted photopolymer or other additive techniques. The lenses are said to compensate for both near and far vision defects. A chamber within the lens is filled with liquid that migrates under slight pressure from the eyelid to change focal length. See Fig. 7.

• The University of Wolverhampton (UK) has applied for a patent on a biomechanical probe which may be used to retrieve blood clots from a patient's circulatory system. Three dimensional printing is key to making the probe tip features, consisting of spiral grooves which provide a vortex to vacuum the clot in. See Fig. 8.

• Syntach AG (Switzerland) describes a surgical method and custom devices for treating disorders of the heart rhythm regulation system in its patent application. Numerous small incisions are made which result in essentially rewiring the atrial cells to provide better electrical response. The instrument is inserted through a catheter and may be fabricated to accommodate the specific condition of the patient.

• The use of polymers rather than ceramics to fabricate dental restorations is the subject of a patent application by CAO Group, Inc. The thermoplastic/thermoset prosthetics described are said to offer the advantages of being able to fabricate multiple teeth at one time, being less prone to cracking and chipping while providing same-day, in-office service.