Date: Tue Jun 18 2002 - 03:56:30 EEST
The latest edition of the RP Patent Alert Newsletter is now available on The
Worldwide Guide to RP web site.
Twenty-six RP patents were issued during the last six weeks and another
nineteen RP applications were published during this period. Altogether,
dental-related applications accounted for fifteen out of the forty-five
grants and applications published, with twelve for a single assignee, Align
Here are a few highlights of patents and patent applications issued from
4/23/02 to 6/4/02:
* EOM Technologies LLC has received a patent on the use of deformable mirror
devices (DMDs) and other types of spatial light modulators to expose
photopolymers in a layerwise fashion. The use of more than one DMD, or a
scanned array of linear DMDs is described as a means of speeding the process
and improving resolution. The patent also describes the use of common DMD
operation schemes such as time division multiplexing to increase resolution
and create specific object features.
* Nanotek Instruments, Inc. has received a patent on a method of rapid
prototyping that uses both the selective deposition of powders and liquids.
The powders can be used to fill large volumes, add strength, etc., while the
liquids may be phase change materials or other types capable of bonding or
coloring the solid particles. The specification also describes how the
liquids can be used to reduce or eliminate stairstepping.
* Nanotek has also received two additional patents relating to another method
of rapid prototyping. Preferably micron or nanometer-sized powder particles
may be projected through a focused energy beam, such as a laser, where they
melt in-flight and are subsequently deposited to produce a three dimensional
object. A second patent describes a process for making such metal
* The California Institute of Technology has been granted a patent on a
method of self-focusing and trapping optical beams in a photopolymer. While
the emphasis is on making fine features in lithography for semiconductors and
the like, the method may also be applicable to stereolithography systems.
* 3D Systems describes a means of reducing distortion in stereolithography in
its patent by using a delay time between exposures. Adjacent layers are not
adhered to each other until the photopolymer shrinkage process is largely
complete, and the waiting time may be used to expose other features so as not
to be wasted.
* Aeromet has received a patent on a multiple outlet feed nozzle for their
LENS-like process. The nozzle uses a gas stream to focus the material.
* IBM has been granted a patent on method of forming solder bumps on
integrated circuits and the like. This technology most directly competes
with selective metal deposition schemes which are addressing similar
applications being developed by, among others, the University of California,
Irvine. However, if reconfigured it could also possibly compete with
processes that make small metal parts such as EFAB now being commercialized
* The US Navy has received a patent for a method of manufacturing novel or
complex damping structures out of generally large viscoelastic particles of
from about 0.05 to 0.5 inches in size. Think selective laser sintering with
ping pong balls.
* MIT's patent describes the fabrication of casting molds with a cellular
void structure that permits the mold to fail in a controlled way to avoid
distorting or rupturing the casting.
* Optomec has been granted a patent on the use of LENS processes to fabricate
structures with differential material compositions and void structures to
produce diverse mechanical and thermal properties. A typical example is an
injection mold with conformal cooling channels and hard-facing surfaces.
* Photopolymer developments continue at a good pace. DSM describes a
material with polypropylene-like properties. Renssalaer Polytechnic
Institute received a patent for a photopolymerizable siloxane compound that
can be used as a release material and has good hardness properties. Workers
at the University of Dayton have developed liquid crystal photopolymers with
glass transition temperatures in excess of 200 deg C and Ciba has been
granted a patent for a photoinitiator system
* 3D Systems' patent describes a phase change material for use in MutiJet
Modeling with increased toughness.
* Align Technology has received another six patents and also another six of
their applications have been published this period. (See below.) The
patents granted during the period all cover aspects of the Invisalign (TM)
orthodontic process. They include means of making a reconfigurable mold,
releasing the aligner from the mouth and easing data processing issues. One
of the more interesting patents describes the use of the aligners as a stress
indicating instrument to determine when the next aligner must be used.
* Technique de Usinage (Canada) has received a patent for a dental implant
drill guide and implant structure using rapid prototyping techniques.
* MIT has received another follow-on patent for comb polymers that are useful
in regulating cell-surface interactions.
PATENT APPLICATIONS PUBLISHED
* POM and/or the University of Michigan are the likely assignees for a patent
application that describes the use of high speed diode lasers in the direct
metal deposition process which is similar to LENS, but uses optical sensors
for closed loop control of the melt pool. The response time enables the
bandwidth of the process to rise from 60Hz to about 20 Khz, resulting in
* Pixelligent Technologies LLC has applied for a patent on the use of two
deformable mirror devices (DMDs) or other spatial light modulators (SLMs) to
expose photopolymers. One device exposes from the top of a vat and the other
from the side to harden the material at the intersection of the projected
patterns. The work seems aimed at two-photon absorption and micro- and
* Optomec has applied for a follow-on patent for the use of multiple nozzles
and beams in the LENS process.
* Creo Products Inc. (Canada) is the likely assignee for an application by
Gelbart. The application describes a stereolithography process that utilizes
thermosensitive materials that are currently used in the manufacture of
printing plates. The purported advantage is to eliminate stray exposure
since these material harden only when a threshold temperature is achieved.
* Micron Technology is the likely assignee for two applications covering the
manufacture by stereolithography of spacers for semiconductor chips and
hermetic packages for semiconductor devices.
* Klaus Schubert et al, associated with Forschungszentrum Karlsruche GmbH
(Germany) have applied for a patent on a rapid prototyping fabricated static
micro-mixer. Such devices have applications in biotechnology and also in the
industrial manufacture of certain chemicals and polymers.
* A photopolymer exhibiting high flexibility after cure and low viscosity is
described in an application by Steinmann et al. The authors have association
* As mentioned above, six applications from Align Technology have also been
published this period in addition to the patents granted to the company.
These applications cover additional aspects of the Invisalign (TM) process,
including selection of a treatment plan from a library of plans, a patient
progressing through a treatment regimen without the need for a professional
to perform successive steps, and efficient data representation and
* Durbin et al have applied for a patent for a process of capturing a dental
model, planning a treatment program and/or a prosthesis, and fabrication of
model. Jeneric/Pentron Inc. is the likely assignee for an application
concerning the mass production of dental prosthetics.
* Hideo Omotani (Japan) has applied for a patent on the use of a
stereolithographically produced model to simulate an airplane wing's
elasticity for flutter testing in a wind tunnel.
* An application by Bradbury et al describes the use of a network, such as
the Internet, to custom design and manufacture biomedical devices such as
implants and drug dosage forms. The authors are associated with Therics.
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
more than 1,000 rapid prototyping patents and applications.
The Worldwide Guide to Rapid Prototyping is located at:
Click the PATENTS button or use the direct link on that page.
Castle Island Co.
781-646-6280 (voice or fax)
For more information about the rp-ml, see http://rapid.lpt.fi/rp-ml/
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