Date: 12/24/01
Good Morning:
The latest edition of the RP Patent Alert Newsletter is now available on our
web site. Twenty two RP patents were issued during the last five weeks and
another fifteen RP applications were published during this period.
Here are a few highlights of patents and patent applications issued from
11/6/01 to 12/11/01:
PATENTS ISSUED
TOOLING
* Honeywell International and its merged partner, AlliedSignal have been
awarded patents for a low pressure injection molding technique for making
metal knife blades, and metal and ceramic threaded components. The method is
said to be advantageous when used with molds fabricated by direct rapid
prototyping processes such as DirectAIM (TM).
MATERIALS
* Numerous patents were issued for stereolithography resin improvements:
Ciba Specialty Chemicals received a patent for a photopolymer manufacturing
process and a resultant product having improved strength. Asahi KK (Japan)
disclosed a resin with superior dimensional stability and lower humidity
absorption. DSM (Netherlands) was granted a patent for materials with
superior heat resistance and adhesive properties. Vantico's patent describes
a low viscosity resin that produces flexible parts. Nippon Soda (Japan) has
patented a clear composition to which a pigment can be added.
MEDICINE
* Neutar LLC has received a patent on an instrument fixturing method which
may be used as guiding means during surgical procedures. The process starts
with a three dimensional image such as a CAT scan of the surgical site and
results in a rapid prototyping-generated structure that mounts to the body
and acts as a surgical template.
* Jeneric/Pentron, Inc. describes the mass production of dental restorations
using RP processes. The invention is said to lower costs and labor content
while providing a stronger restoration. Matching of colors may be carried
out by using colored binders in a three dimensional printing process.
* 3M Innovative Properties Company was granted a patent for a custom dental
tray to be applied to a patient's teeth for applications such as tooth
whitening. The improved fit is said to allow a patient to use the appliance
for a longer period per use and shorten the length of the entire procedure
since fewer individual sessions are required.
* Rapid prototyping can be used in certain cases to create articular surface
replacements for joints. Cartilage cells are cultured in a biodegradable
matrix to replace the wear surfaces of joints. The patent issued to Deutsche
Institute fur Textil-und Faserforschung Stuttgart (Germany) indicates that
the cellular matrix integrates with the exposed surface of the bone.
TECHNOLOGY
* 3D Systems has described a method of extending stereolithography laser life
by using a feedback scheme, and essentially turning the laser off when it's
not writing.
* A method of laminated object manufacturing (LOM) that uses solvent bonding
of layers of plastics has been granted a patent and assigned to North
Carolina State University. CNC routing is used to cut out slices and edges
are shaped to avoid stair-stepping. Advantages are said to include lower
cost of machinery and higher strength objects.
* The Fraunhofer Institute (Germany) has received a patent for a powder
deposition head for use in Laser Engineered Net Shaping (LENS) and related
technologies. The head keeps mass flow rate constant regardless of head
motion.
MANUFACTURING
* Micron Technology, Inc. describes the use of stereolithography as a means
of protecting the surface of semiconductor chips while permitting electrical
contacts such as solder balls to be accessible. The company has also made
several applications for related applications described below and in last
month's newsletter.
* Patents issued to ATL Ultrasound describe several manufacturing methods to
produce micro-machined ultrasonic transducers. One technique is called
micro-stereolithography, but is more accurately laser ablation of build
material in layers from a Teflon carrier onto a substrate.
* Recent news reports describing a bull roughly the size of a red blood cell
fabricated in photopolymer using a method similar to stereolithography by
researchers at Osaka University in Japan have been very impressive indeed.
However, a patent issued to researchers at the University of Connecticut this
month carries a similar multi-photon technique further and resulting objects
are said to be in the 100 nanometer range. The size is suitable for
fabricating structures to mechanically immobilize enzyme molecules, for
cross-linking proteins and for providing means for the delivery of drugs or
biological agents at the cellular level.
PATENT APPLICATIONS PUBLISHED
MANUFACTURING
* The unique abilities of various types of rapid prototyping are exploited in
several patent applications: EFAB is used to make a very small Fresnel
mirror system for use in a 3D laser scanner. The construction of a
scintillation detector array for a breast cancer imaging instrument is
accomplished by fused deposition modeling (FDM). Dams fabricated by
stereolithography are used to contain encapsulants for semiconductors in
another application from Micron Technology, Inc.
TECHNOLOGY
* Teijin Seiki (Japan) has applied for a patent for a method of
stereolithography that is similar to Cubital's solid ground curing (SGC)
technology and to Light Sculpting's technology. A liquid crystal or
electrostatically deposited toner mask is used to layerwise expose
photopolymer as in those methods. However, individual geometric elements in
the layer are controlled and exposed one feature at a time in the
application. This is said to increase accuracy by avoiding large areas of
shrinkage and to lessen certain optical problems.
* A laminated object manufacturing (LOM) method that uses hot-wire cutting of
plastic foams and the like is described in an application by Yang et al
(Korea). The method avoids stair-stepping by the use of multi degrees of
freedom on the cutting wire.
* Improvements to selective laser sintering (SLS) finishes are addressed by
Chong et al (Singapore). They claim to be able to achieve a high gloss
and/or textured finish similar to injection molding using what seems to be a
manual technique.
TOOLING
* Pirelli (Italy) has applied for a patent for a tire mold created using
rapid prototyping. Such methods as selective laser sintering which provide a
porous product are said to be advantageous in making a mold that permits air
ejection during vulcanization.
MATERIALS
* PPG has applied for a patent on a photopolymer suitable for optical and
ophthalmic applications. The material can incorporate photochromic
substances in the matrix.
* Ciba Specialty Chemicals' application describes a photopolymer with
increased green strength, but without limiting photospeed.
* Parkhill et al of CMS Technetronics have applied for a patent for sol-gel
based materials for the rapid prototyping of electronic components by means
of direct writing and laser densification. The materials permit fabrication
of components directly on low temperature substrates.
These are only the highlights! If you're involved with the development of RP
technology in industry or academia, you should find this an easy and
enjoyable way to keep up to date. Our entire patent database now includes
over 900 rapid prototyping patents and applications.
>From our home page,
The Worldwide Guide to Rapid Prototyping located at:
http://home.att.net/~castleisland/
click the PATENTS button or use the direct link on that page.
Ed Grenda
Castle Island Co.
781-646-6280 (voice or fax)
EdGrenda@aol.com (email)
http://home.att.net/~castleisland/
For more information about the rp-ml, see http://rapid.lpt.fi/rp-ml/
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