P16371: Controlled Oscillating Meniscus Test Fixture
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Systems Design

Table of Contents

The Deliverable of P16371 MSD Team

It's expected that this MSD team designs and constructs a device that is capable of meeting the customer requirements as outlined in the problem definition. Specifically, this means that the device must create a stable liquid meniscus, oscillate the meniscus at a frequency of approximately 100 Hz, be capable of utilizing multiple different working fluids, be able to interface with the other subsystems, and it must be reliable. In order to fulfill the customer requirements, it's also expected that the MSD team designs a computer program that allows for adequate control of the device. Therefore, upon completion of MSD II the customer will receive a device that meets his requirements along with a program that is capable of supplying the necessary controls. It's the customer's desire that the device which is being designed and constructed by this MSD team will enable him to conduct his doctoral research.

Team Vision for System Level Design Phase

Anticipated Tasks

For the system level design phase, our team expected to accomplish the following tasks:

Accomplished Tasks

The following items are what our team actually accomplished during the system level design phase:

Subsystem Ownership

Subsystem Owner
Oscillator Alyssa
Circuitry Joe
LabVIEW Rob
Height adjustment Rob
Visibility All
Budget tracking Charles
Injection system Charles

Functional Decomposition

Functional decomposition

Functional decomposition

A PDF document of the functional decomposition can be accessed by clicking here.

Benchmarking

Budget

Budget benchmarking

Budget benchmarking

An Excel Worksheet containing the budget shown above can be accessed by clicking here.

Circuitry

Benchmarking for capacitance sensor

Benchmarking for capacitance sensor

(1) Capacitance Sensor Benchmarking

Height Adjustment

Height Benchmarking

Height Benchmarking

(1) Adjustable Height Platform

(2) Linear Actuator for Copper Chip Height Adjustment

Injection System

Injection system comparison between current syringe pump and a more expensive syringe pump

Injection system comparison between current syringe pump and a more expensive syringe pump

(1) Current syringe pump specifications

(2) Harvard Apparatus syringe pump specifications

LabView

(1) NI cDAQ 9712 Specification Sheet

(2) NI 9205 Analog Input Module Specification Sheet

(3) "Rules to Wire By" NI document for Labview Best Practices

(4) "Top 5 Rookie Mistakes" NI document for Mistakes to Avoid

Oscillator

(1) "Action of low frequency vibration on liquid droplets and particles" by Bennes et al

(2) "Electrically Deformable Liquid Marbles" by Bormashenko

(3) "Cassie-Wenzel Wetting Transition in Vibrating Drops Deposited on Rough Surfaces" by Bormashenko et al

(4) "tudy on the characteristics of contact line and liquid film in rectangular microgrooves under vibration conditions" by Cao et al

(5) "Vibration of Submillimeter Size Supported Droplets" by Celestini & Kofman

(6) "Electric field-induced oscillation of sessile droplets" by ChengGang et al

(7) "Rectified Motion of Liquid Drops on Gradient Surfaces Induce by Vibration" by Daniel & Chaudhury

(8) "Ratcheting Motion of Liquid Drops on Gradient Surfaces" by Daniel et al

(9) "Vibration-actuated Drop Motion on Surfaces for Batch Microfluidic Processes" by Daniel et al

(10) "Sequential droplet manipulation via vibrating ratcheted microchannels" by Ding et al

(11) "Asymmetric electrowetting - moving droplets by a square wave" by Fan et al

(12) "Driving liquid droplets on microstructured gradient surface by mechanical vibration" by Hao et al

(13) "Vibration-induced Droplet Cooling of Microelectronic Components" by Heffington et al

(14) "Vibration-induced Droplet Atomization Heat Transfer Cell for High-Heat Flux Applications" by Heffington et al

(15) "Oscillation spectrums and beat phenomenon of a water droplet driven by electrowetting" by Lai et al

(16) "Vibration of Liquid Droplet by Surface Acoustic Wave Excitation" by Miyamoto et al

(17) "Microfluidic mixing through electrowetting-induced droplet oscillations" by Mugele et al

(18) "Droplet-wall Collisions (Droplet Generation)" by Mundo et al

(19) "Experimental Investigations on Water Droplet Oscillation" by Nazemi & Hinrichsen

(20) "Vibration of Sessile Drops" by Noblin et al.

(21) "Oscillations of magnetic liquid columns subject to random vibration" by Ohaba et al.

(22) "Oscillation of Liquid Drops Under Gravity" by Perez et al.

(23) "Directing Droplets Using Microstructured Surfaces" by Shastry et al.

(24) "New Method for Measurement of Contact Angle (Droplet Free Vibration Frequency Method)" by Yamakita et al.

Brainstorming & Concept Generation

In order to develop a list of concepts that are capable of fulfilling the identified functions, each individual member of our MSD team developed his/her concepts independently. Then, we gathered as team and combined our concepts, and we also brainstormed some additional concepts. The results of our concept brainstorming are provided below.

Concept generation

Concept generation

An Excel Worksheet that contains the concepts displayed above can be accessed by clicking here.

Morphological Chart

Images of Concept Generation

The chart provided below is a visual representation of our generated concepts.
Morphological chart

Morphological chart

An Excel Worksheet that contains the images for the morphological chart can be accessed by clicking here.

Final Concepts

From the morphological chart provided above, and through many iterations, it was decided that the five concepts shown below demonstrated viable system level designs.

Final concepts

Final concepts

An Excel Worksheet that contains the final concept selections as determined from the morphological chart can be accessed by clicking here.

Selection Criteria & Pugh Chart

In order to determine the top design concept from the five concepts shown above, a Pugh chart was created that compared the following selection criteria:

It was found that the Red Concept was the top design. Thus, our MSD team will pursue the design outlined by the Red Concept.

Furthermore, the Pugh chart shown below compares the top two viable concepts for adjusting the height of the meniscus, i.e., via a crank or a motor, and it also compares the top two viable concepts for inducing oscillations, i.e., a piezo-electric actuator or a cone speaker. It was determined that the hand crank and cone speaker are the top designs for accomplishing their respective tasks.

Pugh chart

Pugh chart

An Excel Worksheet containing the Pugh chart can be accessed by clicking here.

Systems Architecture

Preliminary Design

Preliminary design

Preliminary design

Refined Design

Schematic of refined design

Schematic of refined design

Project Feasibility

Feasibility analysis

Feasibility analysis

An Excel Worksheet containing the feasibility analysis can be accessed by clicking here.

Risk Assessment

List of all identified risks

List of all identified risks

List of all identified risks

List of all identified risks

An Excel Worksheet containing the risks can be accessed by clicking here.

Design Review Materials

Item Link to document
Project readiness package Click here.
Initial customer interview Click here.
Team norms Click here.
Systems level design presentation Click here.
Presentation audio Click here.
Presentation feedback Click here.

Plans for the Next Phase

It's expected that the following tasks will be completed by the end of the next phase:

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