engineering design day 2012 - College of Engineering @ The ...

mICRo-FLuIDIC DISpENSE SYSTEm
Interdisciplinary Engineering Design Program
CLASS
ENGR 498A/B
SpoNSoR
Ventana Medical Systems, Inc.
SpoNSoR mENToR/ADVISoR
Kevin Marshall
pRoJECT mENToR
Greg Ogden
TEAm mEmBERS
Luis A Almanza (SE)
Mohamed Ferhaoui (EE)
Rohith Jayaram (ME/ABE)
David R Maynard (ME)
Julie Anne Schmautz (MSE)
ABE = Agricultural & Biosystems
Engineering
EE = Electrical Engineering
ME = Mechanical Engineering
MSE = Materials Science & Engineering
SE = Systems Engineering
TEAm 4953: pRoJECT SummARY
Ventana Medical Systems, Inc. is a leader
in automated tissue diagnostic systems.
These systems use a saline chemical buffer
in the advanced staining process to prepare
biopsy samples for pathologists to identify
cancerous tissues.
The current implementation of the
micro-fluidic dispense system (µFD) at Ventana has some drawbacks and
limitations that need to be improved upon. Due to the high salinity of the solution,
salt crystallization clogs develop on the dispense hardware and impede the
performance of the system. Hanging solution drops on the dispense nozzle are
also problematic because they can cause drops to fall on the label of the slide and
possibly damage it or make it difficult to identify. Additionally, hanging drops allow
for variation in the volume of fluid dispensed on slides. The objective of the project is
to design an automated micro-fluidic dispense system that can reliably and accurately
dispense 20 μl (microliters) of a concentrated saline buffer solution onto a microscope
slide. The allowable preventative maintenance interval should be at least six months
and the cost of goods of the system should be less than $500. The use of electrical
control concepts, fluid mechanics, intelligent material selection, testing techniques and
statistical analysis were used to determine the best solution. Two different dispense
system designs and a mechanical scrubber were implemented as solutions.
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