I worked with Scott Hudson and Jennifer Mankoff on this project with the aim of learning 3D printing, building a 3D printed prosthetic hand and adding modules/functionality to it.
I had always wanted to work with assistive technology, thus marrying my passion for technology, the arts and enhancing the lives of the people around me. This project was the perfect opportunity to learn and make a difference. The E-Nable community has been a great success because the kids that they make these hands for don't reject them as happens with a lot of assistive technology because reasons such as shame, but they happily embrace them as they are made to look cool and colorful.
The two biggest benefits of 3D printing lower-limb prosthetics are the hugely minimized cost and the level of customization that is possible for each user as opposed to mass manufacturing these prosthetic limbs.
Learning how to print
I spent the initial phase of this project learning the nuances of 3D printing since this was entirely new to me. I was assigned to a half-broken printer in the DevLab at CMU, with the aim that in fixing the printer, I would learn more about the process and would be able to fix many of the issues that crop up during 3D printing.
Assembling a 3D printer
Next I bought an unassembled 3D printer from PrintrBot, so that I could go one step further and build the printer from scratch. This was one of the most enriching experiences for someone like me who loves building and problem-solving. Over a course of 2 weeks, I assembled the printer which led to a much better understanding of how the printer was able to print in all three axes, and this came in handy later when one or the other axes were not working as expected while printing.
Modeling and Printing
I was immediately tasked with calibrating my printer, learning a CAD software, and learning how to model in that then eventually print out the object. I found this process very much like any design process or learning any coding language, full of bugs that can be debugged via a logical process. My very first model was the fighter jet pictured above and after several (too many to count) attempts I successfully printed it.
Printing the Hand
I jumped into the process of printing the hand piece by piece. This process turned to be similar to coding, wherein I met with many errors and failures and had to constantly debug the printer and my 3D model.
Assembling the Hand
Over the next month I printed out all the different components of the hand and started assembling it. This included a fishing string, cutters, and whole lot of sanding. The tools of the trade can be seen in the above picture. This process also resulted in many reprints of parts that were not up to the standard.
Enhancing functionality of the prosthetic hand
As this project is a part of a larger project undertaken at CMU, the next goal was to decide on a sensor and then embedding that into the hand. The two sensors that were considered were the Pebble Watch (Classic) and the Simplelink SensorTag by Texas instruments. This is to be used in the next phase of the project to see how the hand is being used, for what activities is it being used and also to study one of the biggest problems with prosthetics currently: abandonment of the prosthetic. This is a huge area of research currently the sensor data can be helpful in understanding when and why these prosthetics are abandoned by the users.
Add-on to hold a phone
This module was designed for people that use the prosthetic hand and they can easily hold the phone in that hand to use it with the other. After some discussion, we just left this at the model level and did not print it since it did not fit in the broader plan for the project.
Adding the ability to write
Brainstormed many ideas on how to let users write with the prosthetic hand as can be seen from the above sketches and 3D models. I was helped by two other classmates for the ideation and 3D modeling for this part of the project.
One major victory for the E-Nable project has been the mass adoption by kids due to its friendly and "cool appearance added to the fact that it helps them with daily tasks. We wanted to reenforce that message and after multiple ideas created a module that connects a small torch to the hand that helps children project the logos and symbols of their favorite superheroes.
Below are some of the sketches and models that I used to create this. The final picture is of me projecting the superman logo onto myself to show how this works.
This project is a testament to the fact that today anyone can learn these skills and volunteer their time and effort to build something that can empower a child to not feel different.