Fiber Repositioning System
NanoDrop
December 11, 2006
Chris Czech
Charles Dielmann
Mark Howe
Dana Kimpton
Christopher Sherman
Who is NanoDrop?
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Manufacture and sell analytical laboratory
equipment worldwide
Used in biotechnology, pharmaceutical, and life
science fields
ND-1000 Spectrophotometer is best known
small liquid sample instrument
The ND-1000
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Uses a flash lamp,
photospectrometer
and proprietary
software to quantify
nucleic acid, protein,
and other biological
compound liquid
samples
Current Operation
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Requires manual labor to reposition the fibers
and place the sample
Sample is loaded in the open position
Sample is tested in the closed position
96 samples analyzed in a typical test set
Open Position
Closed Position
Current Operation
1 to 2 uL sample loading, liquid column formed
for test, sample wiped clean for next test
Project Purpose
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Purpose: To expand customer market by eliminating
human interaction to test samples by automating the
ND-1000 and using a liquid handling robot to place the
samples
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Objective: Miniaturize and
automate the ND-1000's
operations for integration into a robotic testing
environment.
Secondary Objective: Allow for future development of
a liquid sample wiping system within the design.
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Customer Wants
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Repeatable vertical and horizontal alignment
No unprotected fibers that could interfere with
motion of robot
Compatible with Labview
Potential for future liquid sample wiping system
Ease of loading the liquid sample
Project Metrics
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1) Repeatability: within 1/100th of an inch
vertical and horizontal alignment
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2) Distance between top and bottom pedestals:
2/10,000th of an inch
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3) Miniaturize: base dimensions to match the
footprint of a 96 well uL sample plate
Design Concept
Linear-Actuated Translating Arm Design
Upper
arm assembly kept
down close to the rest of the
device, not rotated into path
of robot.
Uses
a linear actuator to
provide back and forth
motion suited to addition of a
wiping system.
Subsystem Design
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Five subsystems within the overall design
Each is critical to the success of the design
Housing Subsystem
Dimensions:
5” long 3.5”
wide 4” tall
Houses
circuit boards and
spectrometer
Mechanism
components
mounted on top.
Lamp and Lamp Mounting
Keeps
center of gravity
over linear actuator.
Arm
mounts to actuator
via existing holes in
actuator slide.
End
of arm has rolled
edge for fiber protection.
Arm Movement and Alignment
Upper Sample Pedestal / Fiber
Flash
Lamp
attached to linear
actuator via arm.
Total
of three
inches of travel for
loading and wiping
cycle.
Lower Arm Assembly
Lower Sample Pedestal

Moved by solenoid
Uses
ball slide
assembly to allow
vertical motion while
constraining other
degrees of freedom.
Control and Data Acquisition
Controlled
via Labview
software.
Communicates
via
USB.
Actuator
controlled by
Allmotion component.
Lower
arm assembly
and lamp controlled by
Spectrometer.
Wiping System
Suggested
possible
design for future
development
Continuous
strip of
material pulled forward
by hook on arm
Prototype
includes a
pair of pads for
temporary wiping
system.
Completed Assembly
Picture
(left) of
Upper Arm
assembly in
sample testing
(middle) position
Picture
(right) of Housing assembly
Video of Prototype
Prototype Validation

Two validation tests performed to determine the
accuracy of the prototype in the x, y, and z
alignment of pedestals
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Test 1: alignment pin used to determine the accuracy
in the x and y directions (dropped through bushings)
Test 2: capacitance meter used to determine the
accuracy in the z direction
Third test to determine the signal strength
through the sample
Data Analysis
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Test 1: 96 trials
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Test 2: 48 trials
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Alignment pin slid through two bushings 96 out of 96 times
without adjustment
100% accuracy in the x and y directions
Reference voltage for 0.2 mm: 4.0
Average voltage: 4.057
Required range: 3.8-4.2 to be within 1/100th of a mm
Well within range
Signal test: 24 trials for each solenoid position

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Most accurate when the solenoid in down position
(compared to the up position)
Standard deviation between signals: 40.0
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Due to variation in size of the sample tested (close to 1 microliter)
Cost Analysis
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Total cost: $3,874
Total UD cost: $959
Path Forward
Deliver
prototype to NanoDrop on Friday
(December 15, 2006)
This
marks end of team involvement
Continued
development of the wiping system by
NanoDrop
Modifications
to design to make it easier to mass
produce
Integration
testing with a laboratory robot
Questions?
Benefit to Company

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Appeal to a broader range of customers by
eliminating human interaction when testing
samples
Automated instrument integrates with x-y-z
robot used to dispense samples
Labview Main Controller
Testing Procedure 1
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Test 1: x-y alignment accuracy
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Remove fiber optics from bushings.
Start actuator motion.
Pause motion at testing position.
Drop alignment pin (0.125” diameter through top bushing
(0.126” diameter).
If alignment pin does not drop through bottom bushing,
loosen screws that attach the solenoid to the base until pin
drops through. Tighten pins in this new position.
Record whether pin dropped without adjustment or if
adjustment was needed.
Resume motion of actuator.
Repeat 96 times to simulate a typical testing set.
Testing Procedure 2
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Mount capacitance meter to the top plate
Initiate actuator motion and pause at the testing position
Establish 0.2 mm gap using feeler gage
Click check gap on the Labview code and record reading for
voltage reference
Unpause the actuator motion
Initiate motion, pause at sample, check gap, unpause motion
Repeat the above step 48 times
Write to file
Find standard deviation and average of all tests using the
reference voltage
Signal Strength Test

24 tests run with water sample
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24 tests run with water sample
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Place sample on bottom pedestal in popped up position
Record the signal strength from the photospectrometer
Place sample on bottom pedestal in popped down
position
Record the signal strength from the photospectrometer
20 tests run without water sample in popped down
position
Find the standard deviation of the tests
Exploded View of Prototype
Flow Chart