156B Week 3

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

• • Sponsor and consultants faithfully agree with Ideal Gas Law calculations

    • Piezo stroke spec defined: 6 microns

  • Found stateside piezo manufacturer

  • Amplifier should arrive in Germany by 4/17 and requested to be shipped immediately upon arrival.

  • Pogo pins should begin arriving towards the end of next week.

  • Reference Microphone is in the process of being ordered.

  • DUT holding insert machining begins Monday

  • Motor mount final design imminent

Accomplishments from Previous Week

• • Updated model for test chamber to reflect changes requested by the sponsor - Chris

  • Got a separate quote for a reference mic and working with sponsor to make purchase - Chris

  • Ordered/Got samples for pogo pins

  • Found stateside piezo manufacturer

  • Finalized calculations for piezo stack displacement

  • Began beginning sections of report

  • Made solidworks models for motor mount

  • Researched the dual hybrid amplifier

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

• • Develop and update web design, Cover page, Multimedia page, Reports page, References (Russ)

  • Order o-rings for testing (Jenessa)

  • Make sure all involved parties are up to speed with progress (Kyle)

  • Clearly outline and define ALL necessary components for final design, to great detail (Jenessa)

  • Define supporting structure for piezo actuator (Russ)

  • Begin build of supporting structure (Russ)

  • Order any necessary parts for supporting structure (Russ)

  • Membrane deign and machining (Kyle)

  • Order GRAS mic, per sponsors request (Chris)

  • Machine DUT holding insert (Chris)

  • Order piezo actuator for testing (Kyle)

  • Define piezo for final design, per our sponsors decision to follow Ideal Gas Law calculations (Kyle)

  • Develop plan to assess any components which have not been accounted for (Jenessa)

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

• • Modifications to MEMS test bed (in person 4/7/15)

    • All MEMS oriented in the same direction (not all with port to center)

    • Counter-sink above each MEMS so that holes are not straight to the MEMS port

    • Rather than using insulated pogo pins use piece of vesspel provided by sponsor for test bed. This will be an insert into the test bed holding the MEMS and pogo pins.

      • Models updated 4/9/15

  • Sponsor requested reference microphone response curves for current microphone and GRAS microphone. If the response of current mic meets his requirements we will use that instead of purchasing the expensive GRAS mic. (in person 4/7/15) Response curves sent 4/8.

  • O-ring (in person 4/7/15)

    • order sample of multiple o-ring materials and test them

    • Different shores

    • Define pre-compression requirements

  • Piezo stack (in person 4/7/15)

    • Look for another stateside supplier/manufacturer of piezo actuators

    • Not American Piezo

    • Look closely at plunger/membrane connection for failure possibility

    • Consider custom actuator casing

      • Flat end for direct connection to o ring

      • Flip actuator?

  • Consider using Vespel material for machining for MEMS chamber due to issue with pogo pin insulation.

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

• Look into different o-ring materials

• Instructor has done 500kHz with piezo so 20kHz should be possible, contrary to what American Piezo rep said on the phone

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

• • Haven't received Design Proposal Feedback

Risks and Areas of Concern

• Proper mounting and alignment of piezo stack

  • Piezo stack precompression requirements

  • Hybrid amplifier operation

  • Lead time

  • Piezo membrane machining

Resources or Information Required but not Available

• • Dynamic piezo actuator consulting

  • Affordable piezo actuator for testing

Schedule

• • Describe upcoming milestone

  • Update Gantt chart.

Budget (list amount spent and amount remaining)

• • • Spent

      • <$100

    • Remaining

      • ~$5,000

Progress on Report and Webpage

• • Completeted rough draft of :

    • Background

    • Review of existing design solutions

    • Statement of Requirements

    • Deliverables

    • Formatting

    • Title page