156A Week 10

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

● Stingrays have a small, barbed stingers on their tails that they use to sting when threatened

● Making something to stop a stingray sting is a complicated materials problem

○ Stepping on a stingray with a protective shoe will still kill the ray regardless

● Deterrents are another option but will require a live stingray to test with.

○ Stingrays can sense changing magnetic fields, see lights underwater, and hear so with a live ray we can test deterrents within these categories

● Our sponsors are 3 alumni who are surfers and beachgoers and wish to avoid stingray stings

Accomplishments from Previous Week

1. We went fishing with the sponsor trying to catch stingray.

a. Not very successful, only got a flounder

b. Looking into both better fishing techniques and access to aquariums

2. Brainstorming stingray sting deterrents

a. Smell based

i. Try various foods (eggs, spices, coffee)

b. Magnetic / Electronic

i. Talking to experts can work as a “soft” risk reduction for this

c. Sight based

i. Flashing lights

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

● Finish individual analysis (entire team)

● keep trying to catch Stingray (entire team)

● Finish final risk reduction report (entire team)

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

1. Sponsor and our team will keep trying to catch a stingray

a. Not the most reliable but will give us the best access to testing and recording

data ​if ​we can catch one

2. We may try to buy stingray from other people.

a. Some fishermen sell them live but supply is coincidental

3. Trying to contact Scripps or Birch Aquarium

a. This will help us narrow our brainstorming and potentially give us new ideas

b. Possibly giving us access to a live stingray to test on

c. Experts will help determine what might be inadvertently harmful to the rays

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

● If a water shoe behaves like a fabric, will we have something behind the fabric? A small barb would otherwise go through a fabric pretty easily.

● There are materials used in medical fields to "simulate tissue". These gelatinous materials could be used in our testing setup to see how far it goes into “flesh”.

● Pendulum impact is measured in momentum, so there will need to be conversion/calibration to get this in units of force

● Building a pendulum might be easier/cheaper than buying one

○ Found a very cheap setup with help from the sponsors

● Access to stingray testing is crucial for picking a route to follow ○ Working on both the fishing and captive stingray testing

● How will an electromagnetic field be large enough to ward off stingrays?

○ Individual component analysis

Risks and Areas of Concern

1. Not easy to catch stingrays in winter, secondary and tertiary testing methods may be necessary.

2. Difficulty obtaining certain materials for testing, will be assessed with individual component evaluations.

3. Avoiding hurting stingrays as much as possible

Risk reduction and milestone

● Keep trying to catch stingray with a sponsor.

● Calibrating the pendulum

● Provide sponsors with a detailed list of possible solutions, so in our next meeting we can discuss how to test them and more importantly, how to obtain the proper materials.

● We may buy a stingray in the market if we can

● Continue brainstorming more possible methods and share with the sponsor.

Budget (list amount spent and amount remaining)

amount spent $0

Amount remaining $1000

Week 10 presentation slides and progress report