High School Student Creates Prosthetic Hand
"Making and taking things apart is a very common 'cleverness' of boys," write Ros Bayley and Sally Featherstone in The Cleverness of Boys. Easton LaChappelle, 17, is no exception. What sets him apart are the things he makes. What he says started as a "cool idea"-a glove-controlled robotic hand-has now evolved into a prototype of a prosthetic arm. And his work is garnering nationwide attention.
LaChappelle, who lives in Mancos, Colorado, has had several of his prototypes featured by Popular Science, Popular Mechanics, and Make: magazines. He showcased the most recent version of the prosthetic arm at the White House Science Fair in April, at which time President Obama suggested he call the Defense Advanced Research Projects Agency (DARPA) about his creation-a suggestion he promptly acted upon. Now that school is out for the summer, he is in Houston, Texas, interning at the National Aeronautics and Space Administration (NASA) Johnson Space Center to work on the Robonaut 2 project. "I will be working on a lot of the final finger and hand designs and getting everything ready for spacewalks," he explains.
LaChappelle says that dismantling everything he gets his hands on-from toys to televisions-has been a favorite pastime ever since he was a young boy. He wanted to try and understand how things work. He also played with building toys such as LEGO® bricks and K'NEX construction sets. A solar battery charger made mainly from LEGO bricks and motorized cars are among the projects he constructed. "I could make anything I wanted and there were no kind of boundaries for it," he says.
It wasn't until he was 14 that he finally learned how to put things back together, started understanding how they worked, and which components did what and for what reason. LaChappelle says that is also about the time when he conceived the idea of building a robotic hand that was controlled wirelessly by a user wearing a glove. The only problem? He knew nothing about electronics, much less how to transform his idea into reality. He turned to the Internet for guidance. "Electronics, circuitry, programming, CAD design-pretty much I'm self-taught with that," he says. "The Internet is a really great tool for this. There are a lot of sites out there that promote learning and make learning easier and fun in a way."
The prototype is a basic model that cost $350 to construct. The robotic hand was created out of flexible tubing, electrical tape, fishing line, hobby servos, Styrofoam wedges, a radio receiver, and Legos, and is operated by a microcontroller. The control glove is powered by a custom battery pack that attaches to the wrist. It is made from an ordinary work glove from a hardware store with flex sensors that LaChappelle hand-sewed onto each finger of the glove-sensors that he had to learn how to write code for, read with a computer, and scale the readings into motor movements. The sensors are wired to a microcontroller board by which they send wireless signals to the robotic hand's receiver. He says that the sewing project was tedious and involved multiple parts. "There are five sensors with five motors for each of the five fingers." While there are a lot of pieces, parts, and work that goes into building a robotic hand, he says he found that what really helped was to break the project down into smaller bits.
LaChappelle's creation took third place in the 2011 Colorado Science and Engineering Fair (CSEF), Senior Division Engineering. He was a freshman in high school at the time. He also earned a spot on the Popular Mechanics Backyard Genius 2011: The Year's 10 Best DIY [Do-it-Yourself] Creations list.
For the 2012 CSEF, LaChappelle used more sophisticated materials and morphed his creation into a full biomechanical arm with a force sensor and vibrating motor to give the user a sense of touch. "I used better electronics, aluminum, a custom stand I welded, and some really powerful motors," he explains. The model hand was created using CAD, and parts were made using a 3D printer. That arm has movable shoulder and elbow joints and is controlled with an EEG headset. "I tried to make my arm match the strength and ability of a human arm," he wrote in the project abstract he submitted to the 2012 CSEF. LaChappelle won third place in the Senior Division, Best CSEF Project, and first place in the Senior Division Engineering, which allowed him to attend the 2012 Intel International Science and Engineering Fair, where the arm placed second in the Engineering, Electrical, and Mechanical Division.
The impetus for the current generation of LaChappelle's prosthetic arm-the one he presented at the White House-came to him in what he calls an "aha moment" at the 2012 CSEF when he had a chance meeting with a seven-year-old girl who was wearing a transradial prosthesis on her right arm. "She had a prosthetic limb from the elbow to the fingertips," he recalls, adding that her movement was limited to opening and closing the hand, which was done via a myoelectric sensor near her bicep. "Just that prosthetic limb...her parents told me it cost close to $80,000...and she would need two or three of those in her lifetime. That's a lot of money.
"I wanted something cool for me, so that is what I made," he says of his first creation. "But I realized that...[the robotic hand] could transfer platforms almost directly into prosthetics."
So for this year's CSEF, LaChappelle designed and fabricated a self-contained prosthetic forearm and hand with motors in the forearm that he says cost $250 to build. He again used CAD to design the arm, and all the parts were fabricated on a 3D printer, except for the motors, screws, and gears. The arm is human-sized and has human-like strength. "I based it completely off of anatomy, ratios, and size," he says. "The whole arm actually weighs less than a human arm.... [It] is definitely a lot more professional [than the previous version]...," he says.
The control system has also been revamped. LaChappelle says he has now delved into the world of neuroscience as a means for the user to control the arm. He is still using the EEG headset from the previous model. However, he has reworked the system so it can detect blink movement and facial expressions and has combined that with a muscle sensor on the foot, all of which work together to create inputs for and control the arm. The new system is easy for the user to learn and use, he says. "There is this wireless headset that I put on that pretty much reads all the different channels of your brain-from delta, theta, high gamma...and based on some neuroscience I am able to take some of those different channels and frequencies and turn them into a really accurate focus rate." He is still refining his work, but the goal is to incorporate the movement technology into software that is incorporated in the arm "so if someone just got this arm...custom mounted to their socket, they essentially would put on the headset and be able to control the arm. But as they learn with the arm, the arm learns with them.... It customizes to the user."
This version earned LaChappelle second place in the Senior Division, Best CSEF Project and first place in the Senior Division, Engineering, the April trip to the White House Science Fair, and a return invitation to this year's Intel International Science and Engineering Fair in Phoenix, Arizona, where he won a second place award from the Patent and Trademark Office Society and a scholarship to West Virginia University, Morgantown.
So what's next? LaChappelle says he's not done yet. He is already working on the next phase of the hand. He says he plans to try to conceal all the motors within the palm while still maintaining the hand's strength, and improve the control system so the user can pick up objects that vary from as fragile as an egg to something much sturdier, such as a tennis ball. "The sky is the limit with this stuff," he says. "Even with just looking at my original designs, there is so much you can do with it. Patents are definitely in the future; I just want it to be at a more professional stage.... My goal for this is to help people, and whatever way will maximize that is where I want to be."
Laura Fonda Hochnadel can be reached at