156A Week 10

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

●     Currently still performing experiments to understand the material properties of Dragon Skin in order to achieve the fastest cure time. It is determined from last week’s experiment that heat significantly speeds up the curing process.

●     No decision has been made regarding the 3D printer or software.

Accomplishments from Previous Week

●     We tested material property of Dragonskin polymer. We did 3 different tests and took data. The 3 tests were single dot on flat paper, horizontal line on vertical paper, and single dot on heating plate. For each test, we took data at 0 min, 2 min, and 4 min after mixing.

●     We found out that the dragon skin needed at least 20 min to be solidify in room temperature.

●     Put the polymer on a heat plate (~80ํ c), it cured much faster (less than 8 minutes), compared to the room temperature (20 minutes). We also found that the longer we waited after the mixing of polymer, the faster it takes for it to solidify and the less it dropped on the vertical test.

●     For horizontal line on vertical paper, the material dripped the least at 4 min.

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

●     Continue testing material property of Dragon Skin. We will be using an oven set at different temperature and different mix time of polymer to see how to optimize curing speed.

●     Potentially start looking into 3D printing kits and software.

●     Mimic 3D printing with nozzle (vary time between layers and vary temperature)

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

●     The bare minimum of this project is to simply print a strip of soft material using the 3D printer and should be what we are aiming for first. (Gianmarco 11/29/18 in person)

●     We lowered our expectation from building a soft 3D print that can print objects with complex geometry to a strip of soft material.

●     Material testing should be tested in different environments with different time after mixing. For example you can perform experiments in room temperature, oven, and on the heat plate. Also you can wait a set amount of time before using the polymer to see how that affects curing time.(Gianmarco 11/29/18 in person)

●     We started on material property testing of Dragon Skin. This week we did a droplet test in room temperature and on the heated plate at different time after mixing to compare curing time. We also did a vertical droplet test to see how much the polymer droops before curing at different time after mixing.

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

●     To understand and become experts in the material properties of Dragon Skin before making a decision on the 3D printer and software.

●     Started to test the material under different surroundings. We first did a droplet test on a heat plate and in room temperature to measure how long it takes for the polymer to solidify. Then we did a vertical test to see how much the polymer droops.

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

●      Use a paper dot to specify and measure the extension or spread after dragon skin dipped out of the syringe.

Risks and Areas of Concern

●     How to arrange the injection system of Dragon Skin in a way so that we do not need to change the nozzle everytime the printer is done printing.

Resources or Information Required but not Available

●     PDMS  hydrogel

●     Ninja flex

●     LAYFOMM filament w/ visco-elastic properties

Schedule

●      Upcoming milestone: Fast curing method established

●      Update Gantt chart.

Budget (list amount spent and amount remaining)

●      $0 spent

●      $2900 remaining

Progress on Report and Webpage

●     Finished week 9 and 10