January 31, 2017

Happy New Year Everyone!

The PHS InvenTeam has been hard at work prototyping our wallet for the visually impaired. Between this, several exciting opportunities offered by local organizations, public presentations of our progress, and our Mid-Grant Technical Review coming up next month, our hands are full!

New developments in the wallet include the completion of our third prototype of the bill sorting mechanism. In our original concept designs, we had envisioned a funnel attached to a rack and pinion placing each bill into its corresponding slot. However, this method used a lot of space and energy moving the funnel in other unnecessary slots, which also decreased accuracy. Our second prototype involved a piston lifting the bill into the correct slot. While this took up less space than the rack and pinion, the piston itself was rather pricey and used far too much electricity to lift the funneling mechanism into place. The third prototype was a hybrid of both previous designs and introduced the idea of compressing the bills already inside the slot in order to add the new one. Although this design seems to work, we are beginning work on the fourth prototype, which uses a rotary motor to distribute bills while a compression mechanism holds the sorted bills in place. We are optimistic that this will be our final design.

Jessica and Raymond CAD Modeling out sorting device

A 360° CAD model for our sorting system

Another aspect of our project was bill identification. After extensive research and prototyping, we discovered that depending on the age of the bill, the location of the UV identification strip along its length changed. Ultimately, this makes using the position of the strips to identify bills difficult. However, the denominations a user is most likely use with our product, such as five and twenty dollar bills, have not experienced changes in the location of their UV strips over different versions. There has been a change in the strip of the ten dollar bill; therefore, we need to check for the strip in two different locations. The one dollar bill has no strip at all. Because of this, we must use an ambient light sensor to check for the UV identification strips that differentiate the bills.

Grace Tang and Grace Kim building an intake prototype out of legos

Our team has also researched people with visual impairments and how they could interact with the device. Ultimately, we decided to implement an auditory user interface. According to our findings, less than a quarter of people with visual impairments can read Braille. A vibrational interface, although private, would require a significant amount of time to relay information to a user. We determined that an auditory system, implemented through retractable headphones, would be the best way of interacting with our users.

Over the past month, we were honored to have two experts speak with us about the device: Ms. Susan Kramek and Mr. Bruce Wooden. Ms. Kramek is one of our school district’s vision specialists. She walked us through current bill identification and storing technologies and gave us input on how we could design the device so it could be useful to people like the ones she assists daily. Additionally, we were able to meet with Mr. Wooden, a former engineer, MIT alumni, and our first mentor. He provided insightful feedback regarding our prototyping process and gave tips on how to proceed with the design process.

Our visit with Ms. Susan Kramek, our school’s vision specialist

We are honored to announce that the InvenTeam has been invited to Open 2017, Venture Well's 21st annual conference in DC. We will be presenting our device and use this opportunity to spread the word about our device, our goals, and the mission of the MIT- Lemelson Program.

We have been hustling this January! It's been extremely busy for us: preparing for the MGTR, meeting with different mentors, preparing for presentations to outside organizations and ultimately building our device. You can follow our updates on Twitter and find out how you can help by checking out our Website!

-The Poolesville High School InvenTeam