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

Update 57.      BRIEF Highlights 12/9/08 to 3/10/09:

A stupefying 215 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 nearly 5,400 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 RP technology. Here are a FEW highlights from Update 57.

ISSUED PATENTS and PATENT APPLICATIONS PUBLISHED

Technology

• Huntsman Advanced Materials GmbH (Switzerland) has applied for a patent on the technology used in its recently-unveiled Araldite Digitalis rapid manufacturing system. The machine uses a MEMS-based shutter device to cure layers of photopolymer at higher speeds than laser-based vector scanning systems. According to the application, two different wavelengths of exposure light are used: A flash cure at one wavelength is used to hold solidified elements in place, and a second wavelength is used for a longer-exposure final cure. See Fig. 1.

• If an inkjet printer system capable of depositing entire buildings appeared in an animated cartoon it might well come out looking like the technology described in a patent application by inventors Paul Bosscher and Robert Williams. A temporary, four-quadrant cable-stay system is erected from which a large bucket containing materials to be deposited is robotically-guided in three dimensions over a cleared section of ground. The system described in this patent application may allow use of existing materials handled in a relatively simple way. See Fig. 2.

• Siemens Corp. describes a method of handling the vast data transmission requirements that are associated with the decentralized manufacturing of hearing aids in its patent application. Instead of passing STL files around, the inventors propose sending a more concise point cloud and reference file from which the STL file can be locally generated. While the invention is clearly intended for hearing aids, the problem addressed would be similar for other products and fields which may potentially use distributed manufacturing.

• United Technologies Corp. describes a method of making a gas turbine blade having low transient thermal stress. Material properties are graded to compensate for the thickness of the part from its leading to trailing edges. This provides a heating and cooling rate which is uniform throughout the blade resulting in lower thermal distortion. See Fig. 3.

• The Boeing Company describes the use of fused deposition modeling (FDM) to fabricate a customized pressure-intensifying tool to aid in the fabrication of composite parts in a patent issued this quarter. It's yet another example of a niche in the process chain of airplane manufacture being filled by direct digital manufacturing.

• Aylward Enterprises Inc. has had several previous patents issued for pill-handling equipment making use of additive fabrication in addition to its just-published application. Pills are a good example for which processing equipment must handle a large array similar, but geometrically distinct items. The ability of RP to provide parts that directly interface to such products on short notice without tooling might also prove beneficial for other fields, such as food or hardware.

• Murata Manufacturing Co., Ltd. (Japan) has applied for a patent on a photonic crystal band-pass filter for communication applications made by stereolithography. The filter can be tuned over a wide range of frequencies in the GHz region by application of a variable magnetic field.

• Northeastern University describes complex meta-materials with embedded dielectric and magnetic particles made by stereolithography. Depending on the geometry the materials can be used as antennas, nano-circuit elements for optics, RF lenses and in many other applications. See Fig. 4.

• A patent application by Michael Dunn-Rankin describes a novel writing instrument such as a pencil. A logo or other readable marking is embedded lengthwise in the pencil such that it can be read on the surface of the cone formed by sharpening. Since the marking is embedded throughout the entire length, no matter how small the pencil gets the marking can still be read. See Fig. 5.

• REVA Medical, Inc.'s patent describes radio-opaque bio-resorbable polymers. The materials are said to be capable of being made in forms suitable for stereolithography, laser sintering and other additive technologies. The polymers are inherently radio-opaque requiring no fillers, and are useful for such applications as locating stents and other invasive devices.

• EOS GmbH (Germany) has had a patent application published that describes stainless steel powders for use in laser sintering that can be post-hardened.

• Famed inventor Robert Jarvik has been granted a patent for a minimally invasive ventricular assist device. The tiny prosthetic pump precisely fits entirely within the heart within the space of one of the three leaflets of a heart valve. Manufacturing the device starts with three dimensional scanning of the patient's physiology, followed by additive fabrication. See Fig. 6.

• Cochlear Limited (Australia) is the assignee for a patent application describing a hermetically-sealed cochlear implant. Complicated electronics are located within a curved shell produced by selective laser melting (SLM) or other processes. See Fig. 7.

• Stereolithography is used to make a precursor for contact lenses in two patent applications from Johnson & Johnson. While most applications can be covered by injection molding, specialized or custom lenses are said to be made more economically using this method.

• Embryonic-like stem cells derived from teeth may be used for self-renewal of a patient's teeth according to a patent application from Stiftung Caesar (Germany). Scaffolds are generated using additive fabrication into which is incorporated tissue isolated from a dental follicle or wisdom tooth.