156B Week 4

Overview of Status of Analysis, Design, Fabrication, Tests, etc.

• • Optics Design: On hold

    • Awaiting shipment of CMOS sensor to determine final dimensions

    • Awaiting finalization of XYZ translation mechanism to verify performance of optics

  • TIRF Testing: In Progress

    • Testing of different LEDs: color, brightness, diffusion shape

  • Spectroscopy: In Progress

    • Determine dimensions of apparatus

    • Risk reductions testing of photodiodes

    • Calibration of sensitivity

  • Electronics: In Progress

    • LED circuit construction

    • Possible design of CMOS electronics (Steve Roberts)

    • Possible implementation of transistor design for switching between stepper motors

  • Mechanical: In Progress

    • Fabrication of first translation prototype completed

    • Redesign of translation prototype in progress

      • To reduce vibrations and binding

  • Software: In Progress

    • Arduino XYZ stepper code complete

    • Photomontaging Code in development

    • Graphical User Interface (GUI) for Mac iOS in development

    • Graphical User Interface (GUI) for iPad application in development

Accomplishments from Previous Week

• • Redesign of XYZ translation mechanism

    • Implements sleeve bushings

  • Fabricated slide holder for testing

  • Fabricated LED holders for TIRF testing

Goals for Next Week (list names after each item). Use specific and measurable objectives.

• • Determine dimensions/configuration for spectroscopy (Sean)

  • TIRF Testing (Sean, Reggie)

    • Test performance of difference LEDs

    • Determination of critical angle

    • Assess imaging performance

  • Fabrication of new XYZ translation mechanism (Leonardo, Kyle)

  • Consult with Steve Roberts about Electronics (Reggie, Sean)

    • Alternative CMOS electronics solutions

    • Wiring alternatives to cut down Arduino pin usage

    • Proper photodiode circuitry for light intensity measurements

    • Possibility of PCB design for electronics in final prototype

Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)

• • • • Comments from 4/23/12 Meeting:

        • Would like optics to be smaller (to reduce height of overall device), however for time being can allow standard tube length to be used

        • Sponsor is happy with length and width of device, and is just concerned with the height

        • Would like an optics expert's opinion

      • Actions Taken:

        • Since the height is a direct result of the optical components modular design is being used such that if a smaller optics solution is found, the components can be easily implemented with the existing mechanical translation design

        • Spoke to Dave Lischer about optics

          • Commended our solution that achieves 60x with low cost components

          • He said that shrinking down the optics while maintaining the same magnification power will ultimately increase cost (requires expensive parabolic mirror)

Instructor Comments from Last Meeting and Actions Taken to Address these Comments  (indicate date of comments and if via email or in person)

• • • • Comments from 4/19/12 Presentation:

        • Presentation Comments:

          • Would like a reference image to compare our microscope's images to another microscope's image

          • Consider DFM

        • General Design Comments:

          • How will you account for vibrational issues?

      • Actions Taken:

        • In the process of redesigning a more robust XYZ translation mechanism with more precise bearnings to eliminate unwanted vibration

          • Will utilized bronze flanged sleeve bearings

          • Hardware has been ordered and is awaiting shipment

Comments from Other Students in the Class (indicate date of comments and if via email or in person)

• • • • Comments from 4/19/12 Presentation:

        • Vibration considerations/concerns?

          • Clamp or second point of contact in the middle of microscope for vibration reduction

        • Component suggestion: Ruggeduino and rugger motor shield

        • Use gloves to avoid dirty optics

        • Demonstrate the range of motion via a video in the presentation?

      • Actions Taken:

        • Vibration issues have been taken into account and are in the process of redesign and fabrication of a new XYZ translation prototype

        • Clamp to middle/bottom of optics will require another moving rail system

          • Bottom was designed to be free in order to fit functional requirements (moving around the image sample)

          • Believe that vibration can be eliminated from the slop of the upper translation mechanism

        • Gloves and cleaning supplies were used however there are permanent surface scratches on the eyepiece

          • Another eyepiece will be purchased

Risks and Areas of Concern

• • Binding and vibration of XYZ translating optics carriage

Resources or Information Required but not Available

• • Electronics Consulation with Steve Roberts

    • Photodiode Circuitry

    • Proper signal amplification

Schedule

• • Describe upcoming milestone

  • Update Gantt chart.

Budget (list amount spent and amount remaining)

• • Amount Spent: $775.86

  • Amount Remaining: $724.14

Progress on Report and Webpage

• • Drafting Content for Webpage

  • Uploaded Content onto Multimedia Page

  • Uploaded First Draft of Background and Introduction Sections for Report