The next few blog posts are from the last few weeks of the internship! I wrote a blog each week but had little time (and wifi!) to post them.
This week we made a lot of progress on our device. Francis and Andrew (Studio managers) were out of town the whole week for a retreat so we were working independently a lot of the time. We also had a short week (3 day weekend) because of Malawian independence day. On the weekend we got to travel to lake Malawi. It was really beautiful and a huge tourist attraction. The highlight of my weekend was visiting my teammate Demobrey’s home in Zomba. I feel like I’m beginning to get a lot closer with my teammates now!
Day 26
Monday July 2, 2018
Poly Cafeteria
Goals Accomplished
- Designed the power shut off circuit for our device
- Created a proof of concept circuit prototype
Francis and Andrew left this morning to their Rice 360 team retreat. They named myself and Alfred (one of the Poly interns) as the ones in charge while they were gone. We were responsible for arriving early, unlocking the design studio and the office (where all of the electrical components and other expensive tools/devices are kept). We also had to keep track of all of the components that people borrowed and make sure that everyone was making good progress. I’m very honored to have been chosen!
That same day, we were figuring out the circuit for our device. The circuit needs to shut off the suction machine when water overflows from the collection jar. We thought of a very simple circuit using an electrical component that acts as a switch and some metal contacts in water which would also act as a switch/sensor of sorts.
To build our circuit prototype, we used a relay (switch) and a transformer (to step down the voltage from 240 V to 5 V because the relay can only handle 9 V max, and 5V is less dangerous) from a phone charger. At first we were trying to figure out the pin configuration of the relay online, but the wifi isn’t very reliable. Thankfully, I ran into Tebogo (a Poly student who hangs out in the studio sometimes) who explained the pin out of the relay. Quickly after, we got a working proof of concept prototype using a relay, a rechargeable battery, a cup of water and a lightbulb.
I also finally ate lunch at the Poly cafeteria with my teammate Taonga. The Rice interns were worried that the food would make us sick, but it was fine and I will definitely be eating there from now on. It was a very different dining experience. Some groups of friends were piling all of their food into one large food for sharing. Others brought their own plates and forks. We like most others were eating off of styrofoam containers with our hands. I’m really not used to eating with my hands, but I think with time I will get more comfortable with it. It seems simple but there’s actually a technique to eating rice with your hands!
Day 27
Tuesday July 3, 2018
Amazing Goop
Goals Accomplished
- Organized power shut off circuit
- Created “water sensor” part of our device
After confirming that our circuit would work, we began to incorporate it into a working prototype. We did a lot of soldering and used a lot of electrical tape to contain our circuit in a small cardboard box. The small box contained the relay, the 5V phone charger transformer circuit, and the connections to the main power supply (240 V from the outlet).
We also created an airtight jar to contain our contact points (“water sensor”). This jar will then be attached to the suction tubes on the suction pump machine in between the collection jar and the motor. The idea is that when the collection jar overflows, it will overflow first into our device and when the contacts touch the liquid the suction machine will shutoff before any motor damage occurs. Our device jar was just an old peanut butter jar that we punctured holes in to attach the hoses. We used a sealant called Amazing Goop to make our jar airtight and let it dry overnight.
After work we (Rice interns) went rock climbing which seems to be popular among Ex-Pats (foreigners). It was a good workout and a little scary because there was no belay (ropes).
Day 28
Wednesday July 4, 2018
First Success
Goals Accomplished
- Created an airtight water sensor container
- Tested the container for airtightness using a syringe
- Documented our working prototype on camera
When we got to the design studio today, the Amazing Goop sealant on the device jar was completely dry. We tested to see if the jar was actually airtight by covering one end of the tubes while sucking air out of the other tube using a syringe. The container contracted when we did that meaning it was definitely somewhat airtight. We also poured water into the container and flipped it upside down to check for any leaks. There were none.
Afterwards we combined the device jar with our circuit prototype to complete our first working prototype!! We were so excited that we made a video demonstrating how the device would work. The video captured the prototype in action by turning on and off a lightbulb when the copper wires came in contact with salt water (in real life the bulb represents the suction pump machine). Note: We have to add a lot of salt to the water for our device to successfully shut off the machine. (Major drawback of this prototype)
After work today, we went to a café for dinner. The food was really good and there was also a poetry reading. The poetry was written by local Malawian students which was really cool. The topics ranged from school to love to politics.
Day 29
Thursday July 5, 2018
Feedback
Goals Accomplished:
- Obtained feedback on our device from hospital medical device maintenance unit
Since we created a working prototype, we wanted to get feedback on it at the Queen Elizabeth hospital Physical Assets Management aka PAM which is the medical device maintenance unit. We wanted to know what improvements can be made to our water sensor jar (is it air tight, does it obstruct air flow at all/normal operation of the machine?). We also wanted to know how we could improve our circuit.
After visiting the PAM we learned that we may want to add a buzzer to our device so that the nurses will be alerted before the machine turns off. We also want to try different methods of attaching the device to the suction machine so that our device isn’t hanging in midair. Since we want the suction machine to plug straight into our device instead of to the wall, we also talked about the kinds of plugs that each suction machine has so we know what kind of female outlets to buy for future prototypes.
Day 30-32
Friday-Sunday
Republic day weekend
We woke up bright and early Friday morning to go to Lake Malawi in Mangochi. We hired a private minibus to take us there. The drive was 5 hours long. When we finally arrived we went straight to the lake. It was really beautiful. The nights were also really nice because we could see so many stars. We tried some of the local fish and went on a boat tour of the lake. We also got to go snorkeling and we fed an eagle. It was a nice weekend!
On our way home I stopped in Zomba, Demobrey’s hometown, to visit his family and their home. His mom’s name is Shalome and she made us Nsima with fish and veggies. I’m really thankful to Demobrey for taking me to his home. It was a very great experience. I truly got to see the real, everyday Malawi not the tourist part of it (Safaris, the Lake, etc). It was really nice and I hope to be able to do this with more of the Poly interns. I can’t visit many of the interns families since many of them aren’t from Blantyre. For example Taonga is from a city in the north (about 12 hours away). However, I plan on visiting their hostels (their temporary rooms/dorms).
