"Perspectives" is a column co-authored by Terry Wohlers. The
following was published
in the February 2002 issue of Time-Compression
Technologies magazine.
New advance and trends yield surprises.
Few new technologies have impacted product development as much as rapid prototyping. This impact continues to increase as organizations discover new, creative uses for the technology. As RP further develops, additional applications will be discovered, and it will continue to expand into industries that have largely ignored or resisted it.
Today, methods of rapid prototyping are being used in applications and in industries that range from dentistry, orthodontics and medicine to Hollywood filmmaking, hearing aid production and MicroElectroMechanical Systems (MEMS). The following examples capture the breadth of new and unusual applications.
Interesting Applications of RP
Dentistry
Cynovad (Montreal, Canada) announced an agreement to purchase several
hundred ThermoJet printers from 3D Systems (Valencia, CA), which are to
be re-branded as WaxPro. Cynovad is the exclusive reseller of these
machines to the more than 50,000 dental labs around the world for the
production of crowns, bridges and other types of dental restorations.
The machines produce wax patterns needed for the investment casting
process.
Formula 1 Racecars
In England, a service provider named 3T RPD (Berkshire, UK) is using RP
to supply parts for the Jordan-Honda Formula 1 racecars. Some of the 20
different parts are used as prototypes, but many are produced as final
production parts for cars built to win races. These parts include
replacement panels that form aerodynamic skins, cooling ducts and
electrical boxes. According to 3T RPD president Tim Plunkett, the
company is supplying Jordan-Honda with an average of 35 laser sintered
parts per week with a typical deliver of only 48 hours (see Figure 1).
|
|
|
Figure 1: Front end of a Formula 1 racecar. |
Custom Filters
Using 3-D printing (3DP) technology from the Massachusetts Institute of
Technology (MIT), Specific Surface (Franklin, MA) is manufacturing
highly complex ceramic filters that are applied to everything from
making soy sauce to filtering diesel emissions. Using its CeraPrint
process, Specific Surface produces filters in quantities of 10 to
100,000.
Artificial Limbs
Bill Rogers of the University of Texas at San Antonio conducted a study,
sponsored by the Veteran's Administration, to determine whether
selective laser sintering (SLS) can produce superior sockets for
below-the-knee amputees. Clinical results indicated that the amputees
were pleased with the fit, comfort and functionality of the sockets that
include design features feasible only through RP.
Medicine
Therics, Inc. (Princeton, NJ) uses its 3DP license from MIT to
manufacture medical products that include time-released, customized,
oral medications; resorbable Òscaffolding;Ó and implants for
cartilage, tendon and bone substitutes. Therics makes it possible to
produce resorbable tissue structures, such as a bone graft or an eye
socket, from CT scan data using the company's proprietary CADLink
conversion software and TheriForm 3-D printing process.
Toxicology Studies
Doug Greenwood of Product Development Service (Durham, NC) has used DSM
Somos' (New Castle, DE) WaterClear material to model a human nasal
passage for CIIT Centers for Health Research. The transparency of the
cured photopolymer permits visualization of air and particulate flow for
improved understanding of chemical interaction with the nasal membrane.
Both companies believe that the complexity of this internal passage
makes it nearly impossible to physically model using any method other
than RP (see Figure 2).
|
|
|
Figure
2: Nasal passage |
Miniature Parts
RP processes are producing very small parts, some as tiny as a red blood
cell. The University of Southern California is using a process it calls
electrochemical fabrication that electro-deposits nickel layer-by-layer
using a masking technique. With this method, it is possible to produce
working mechanisms that measure 100 microns (0.004 inch) in height.
In Duisburg, Germany, a company named microTEC can produce 150 miniature photopolymer parts per hour using its proprietary stereolithography process. Layers are an amazing one micron (0.00004 inch) in thickness.
Meanwhile, researchers at Osaka University (Osaka, Japan) are using two lasers and liquid photopolymer to produce very small parts. Remarkably, they were successful in producing a detailed representation of a bull that measures 10 microns from tail to nose - the size of a red blood cell.
World's Smallest Robot
Using stereolithography, Sandia National Laboratories (Albuquerque, NM)
has built what it believes is the world's smallest untethered robot. The
mobile unit weighs less than one ounce and measures 0.25 cubic inch.
Hearing Aids
Many of the major manufacturers of hearing aids are in the early stages
of using RP to mass customize their products in impressive volumes. Some
of these companies produce more than 1,000 in-the-ear hearing aids per
day, each being unique in its shape and size. A silicone rubber
impression of the ear canal is digitized with an optical scanner, which
leads to an STL file and RP for the rapid production of the hearing aid
shell.
Injection Mold Design
Companies are using color 3-D printing from Z Corp. (Burlington, MA) to
optimize the design of injection molds. Using mold filling simulation
software, such as that from Moldflow, it is possible to output files
that can be read into Z Corp.'s Z406 and Z402 color 3-D printers. The
result is a model that visually represents mold filling and cooling
characteristics - a powerful aid for design and evaluation.
Burn Masks
RP is being using to produce custom-fit masks that reduce scarring on
burn victims. The process begins by digitizing the patient using
non-contact optical scanning. The scan data is used to produce an RP
model of a mask that fits perfectly to the patient's face.
Developments and Trends
These examples highlight just a few of the developments in RP and some
of the new and exciting applications. This information, coupled with
research into ongoing developments, illustrates several interesting
trends.
RP for the Production of Finished
Manufactured Parts
An increasing number of companies have demonstrated RP's ability to
produce finished goods. These progressive companies have laid the
groundwork for others to follow. Additional examples include: Bell
Helicopter (Fort Worth, TX) using RP to produce metal castings for its
helicopters; Technikon Free State (Bloemfontein, South Africa) using
laser sintering to manufacture a monitoring device for fitness centers;
and a user of Stratasys' (Eden Prairie, MN) FDM Titan producing a
polycarbonate replacement pulley for an industrial belt sander.
Growing Demand in the Medical Industry
Many medical applications demand some level of personal customization,
and RP has demonstrated the ability to address this need. Andy
Christensen of Medical Modeling LLC (Golden, CO) says the demand for RP
models in the medical industry has doubled during the past two to three
years. Align Technology (Santa Clara, CA) has developed more than one
million RP models, using its stereolithography machines to produce its
Invisalign invisible plastic aligners for straightening adult teeth.
Separately, Interpore Cross International (Irvine, CA), a medical device
company, is using seven ModelMaker machines from Solidscape (Merrimack,
NH) to manufacture spinal implants.
Micro Parts
With computers and hand-held electronic devices shrinking, the appetite
for small parts grows. RP's style of building parts in layers, coupled
with lasers, makes it possible to produce very small parts and
assemblies that are highly complex. The number of activities in this
area suggests that a trend is developing for the production of miniature
parts through RP for wide ranging applications and products such as
actuators and sensors.
The range of new and usual applications of RP continues to expand. These uses, combined with the many new developments and innovations around the world, are leading to advances and trends that are reshaping the RP industry as a whole. Brace yourself because this is only the tip of the iceberg. Growth into new markets and industries will redefine the role of RP. This, in turn, will alter our future in ways that are difficult for many of us to envision.
Share Your Feedback On This "Perspective" With Us! Send your opinions, questions and comments to christina@ctipublishing.com.
