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Note:
We have been involved in the development of with many hand-held and bench
top devices. A number of these have
utilized our expertise in micro and macro fluidics, optics, and
quantitative spectroscopic detection for analytical analysis systems.
These include bio-toxin detectors based upon paramagnetic particles and
quantum dot fluorescence, and a blood analyzer using optical absorbance to
measure biochemical reaction times. In addition, we have been involved in
the design of a military GPS, several models of laboratory pH meters, and
a number of lab instruments that involve fluorescence and/or reflectance
measurement. We have also developed a number of very successful insulin
pumps, ambulatory infusion pumps, and hand-held controllers for implanted
medical devices.
It is important to
work with a contractor who has experience developing a product similar to
yours.
If your goal is to develop a robust
and manufacturable product that meets your requirements in the shortest
period of time, previous experience is key. Omnica has been helping
companies develop their concepts for 24 years, and a number of our group
have been in the design and engineering business for considerably longer.
Having developed hundreds of products, it’s not surprising that we see
many with common features. In addition to more accurate proposal estimates
(because we have a good idea of what kinds of challenges we are facing), our
experience provides a higher probability of success. 
Waterproofing
a product can be a difficult goal to achieve.
They offer
unique design challenges, given the fact that the usual goal is to pack
everything in the smallest possible volume. Also, contrary to what would
seem like a reasonable assumption, development of
a waterproof enclosure is not an intuitive process. If you
haven’t been successful at doing it before,
it is very difficult to execute successfully.
Waterproofing
was only one of the challenges
Omnica conducts a
pre-production review for a client company.
Not long ago, there was a project that came to us for a pre-production
review, which demonstrated the value of our experience. The client company
had worked with us in the past, and asked us to review one of their new
handheld enclosure designs in terms of waterproofing and
manufacturability. The preliminary electronic
design was nearly complete, and the process of building the surface mount
boards was about to be started.
A careful look
at the design revealed a number of areas where we could help.
First of
all, it was clear that the proposed design would not pass the underwater
immersion requirement. The seals would have to be redesigned, the case was
too flexible for long-term integrity, and the way the two halves of the
case joined would have to be changed. Beyond waterproofing, there
was a manufacturability question regarding the placement of an infrared
lens in the case.
We
re-configured the o-ring seal, incorporated some internal shock mounts,
and provided interlocking features to stabilize the pager-sized case. Our
Mechanical Engineers worked with the customer’s vendors, and redesigned
the way the I.R. (infra-red) communication lens installed so the device
would be manufacture-friendly.
A
major issue was the two circuit boards and placement of the specified
components.
It
turned out that we weren't done yet! When
our designers looked at the proposed double-sided circuit boards we saw
that they were too thick to fit inside the handheld case. To accommodate
the boards as the original electronic engineers had envisioned, the
eventual case size would need to be 50% thicker
than originally planned. The entire case would need to be
redesigned if we couldn't find a solution.
We
reasoned if we could modify the placement of the components, maybe we
could “nest” the double-sided companion boards to eliminate the extra
thickness. Our approach was to solid-model the
boards and their surface-mount components using our SolidWorks™ CAD
program.  In
the computer we could test different placement schemes to see if there was
really room to nest the components without physical interference.
We
combined stereolithography and electronics
During this process we had ongoing communication with our client company
to make sure the proposed placement changes would be okay. When we
believed we had the solution, we tested the design changes by building
3-dimensional stereolithography models to confirm the fit. See picture
at left. The next-generation boards were configured with the
components arranged as we suggested.
In the end, we
achieved the goals of our client company.
The
surface-mount boards fit closely together without any contact between
component leads and traces. The result was a densely-packed product,
within the target size range. The device passed
waterproof testing on the first round. It is doubtful this
project could have been done in the available timeframe without the power
of solid modeling and rapid prototyping methods.
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