156B Week 3

Progress Report Week 3

This week's plan is based on our preliminary design. We started 3D printing our first prototype last week. What we need to do this week basically goes in two directions. The first direction is to prove the feasibility of our design through prototype. For the time being, there are two test schemes. First of all, we need to test the vertical motion of the needles. Also we need to make sure the store tank is stationary inside of disposable cartridge. Second test that we’d like to test if there is any agent leakage while the motion is occuring. Since this is just a prototype, it does not really fulfill the proper manufacture requirements or standards. Just for the design verification purposes, we will take this into our consideration also. If we find any problems in this process, then we need to modify the design in time. In addition, our design will be changed according to the needs of sponsors. The second direction will be set up a face to face meeting with our sponsors and introduce our preliminary design to them and to see if they are satisfied with this design.

Figure 1: Microneedle system CAD design

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

For upcoming testing, we will focus on how to determine the breaking force and the force that causes plastic deformation of the hollow needles at various sizes (this test scheduled in end of week 3 and beginning of week 4)

• • Experimental Setup: the storage tank will connected with the syringe. Used water as a testing liquid because it has similar characteristic compared to plasma. Then force will be applied to push the syringe (the weight will be measured and recorded), then the mass flow rate will be recorded and documented. 

Also, the team will conduct a mass flow rate experiment on testing the fluid flow through the 3D printed storage tank to determine and finalized its characteristics and design parameters (this test scheduled in week 3: Tuesday, Wednesday, and Thursday).

• • Started the thinking process of a test bed to test the needles they currently use as a base test, and use our optimized hollow needles as a comparison

  • Setup experiments on testing the behaviors of the needles. The characteristics that the team focuses on, but not limited to, are the depth of the microneddle’s penetration through different objects such as pig-skin or jelly, or something that is similar to the stiffness of the human skin (this test will be scheduled in week 5);

  • For testing the deformation of the hollow needle, we can measure the amount of displacement of the bending at various applying force. Also, we need to determine the breaking force, or the force at which break/fracture the needle; and the value of the force that permanently deformed the needle.

Accomplishments from Previous Week

• • 3D printed the storage tank for testing.

  • Recieved the hollow needles from the sponsers.

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

• • Communicate with the manufracture on the construction of hollow needles.

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

• • Arranged weekly meeting to update and assist with the project.

  • Need to focus on hollow needles and agent delivery (no insulation)

  • To provide all the necessary needs and supplies such as hollow microneedles.

  • Receive the hollow needles (the team will start testing the characteristics of the hollow needles)

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

• • Primary focus was to explore top priorities; talk to the sponsor about it.

  • Force testing for hollow needles deformation point.

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

Risks and Areas of Concern

• • The structure or materials of the needles may deform/break during injection.

  • The needles arrangement across the device. 

  • Leakage of agent from the device

  • Interference between hollow needles motion and agent motion

Resources or Information Required but not Available

Schedule

• Ganntt chart link: https://docs.google.com/spreadsheets/d/1Rsep4Byl5w-ZwaOZbzAgdEkJXQq7UqNQCz2TDspl4I8/edit#gid=0

Budget (list amount spent and amount remaining)

• • • $108 Dr.Pen device

    • $8.99 tattoo needles

    • $12.29 Syringes

• • Money left = $3070.72

Progress on Report and Webpage