30 US Patents Issued Related to Rapid Prototyping from 2/20/01 to 4/10/01

From: EdGrenda@aol.com
Date: Tue Apr 24 2001 - 05:27:11 EEST


The latest edition of the RP Patent Alert Newsletter is now available on our
web site. An extraordinary 30 RP patents were issued during the last month
and a half which may be some sort of record. Here are a few highlights of
patents issued from 2/20/01 to 4/10/01:

* MIT has been granted a patent for the fabrication of electromagnetic
devices using inkjet technologies. The applications are aimed towards
wearable computers, actuators and similar applications, but the claims are
broad and could impact work by others in the field.

* The present author, Ed Grenda, has been granted the first patent which
addresses practical issues associated with electrophotographically-based
(xerographic) rapid prototyping. The method combines high resolution and wide
materials choice with high speed fabrication. The patent offers numerous
practical approaches for adapting xerographic processes to the needs of rapid
prototyping. Its 1994 application pre-dates nearly all other work in the

* Ingo Ederer of TU-Munich has received a patent for a rapid prototyping
method which may greatly speed up inkjet-based processes. The technique
involves building shallow layerwise dams of support material which are
flooded with object building materials. The process combines features of
Solidscape / Sanders machines with the work of Richardson of M-Cubed and

* A couple of interesting rapid prototyping patents have come out of work on
printing plates and related areas. Spectra Group Ltd's patent uses a
deformable mirror device (DMD) to expose thick photopolymer layers to
generate gray scales, colors or variable mechanical properties. The patent
provides a useful survey of color generation in photopolymers and seems aimed
mainly at the manufacture of decorative objects, or tactile data and pictures
for visually impaired persons. Creo SRL (Canada) has patented a form of
stereolithography based on thermosensitive photopolymers. The main
application described is the generation of flexographic printing plates, but
the method may have much wider applicability. The use of thermosensitive
materials allows for exposure at selected depths within a vat.

* Some important tooling patents have issued: AlliedSignal has been granted a
patent for a method that is described as similar to aluminum-epoxy tooling,
but allows low pressure molding of complex, near net-shape, ceramic and metal
parts. Brookfield Innovations' patent describes a method of producing
injection mold tooling which probably most directly competes with the KelTool
(TM) process. Resultant molds provide a combination of conformal-like
cooling, lower cost of materials and high (0.1%) accuracy. Rapid prototyping
is used to form the base of the tool and CNC is used to produce working

* Several dentistry related patents have been granted, including a follow-on
patent to Align Technology for its orthodontic system based on rapid
prototyping generation of molds for tooth alignment appliances.

* Numerous patents in the medical area have issued, including an implantable
knee prosthesis, RP generation of vascular models, and a couple related to
tissue engineering applications. MIT has been granted a follow-on patent for
comb polymers which are useful for differential cell attachment to engineered
organs, and another for rapid prototyping-generated micro-organ arrays.

* Several patents have been granted for improvements and variations of
existing commercial methods of rapid prototyping. Norma Jean Iverson's (Pure
Fluid Magic, Inc.) patent describes how to use stereolithography to make high
precision objects. The Fraunhofer Institute has extended selective laser
sintering to the production of fully-dense metal parts by means of localized
melting. The method uses short overlapping scans to create uniform high
temperature melt zones. 3D Systems has received a patent for the support
structure used in its Multijet Modeling technology.

There were numerous additional developments in photopolymer materials,
Laser-Engineered Net Shaping (LENS), metal jetting systems, stereolithography
exposure systems, etc. 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.

The frequency of publication of the RP Patent Alert Newsletter on The
Worldwide Guide to Rapid Prototyping web site has been increased from
quarterly to approximately monthly. We hope this change will let you keep up
to date in a much more timely way and also be quicker and easier to absorb.
Our main patent database includes more than 700 rapid prototyping patents.

>From our home page,

The Worldwide Guide to Rapid Prototyping located at:


click the PATENTS button or use the direct link on that page.

Ed Grenda
Castle Island Co.
19 Pondview Road
Arlington, MA 02474 USA
781-646-6280 (voice or fax)
EdGrenda@aol.com (email)

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