PriMA Prosthetics developed a 3D printed myoelectric prosthetic arm that is strong, lightweight, and life-like in appearance and function for under $1,500. The arm uses DC motors, force sensors, and myoelectric sensors to allow for a full range of motion and gestures through machine learning algorithms. It was designed through client and industry surveys to be comfortable, easy to use, and mimic the motion of a natural hand. 3D printing allowed for complex contours to be manufactured quickly and inexpensively.

1. PriMA Prosthetics – 3D Printed Myoelectric Prosthetic Arm
Clyde Brown, Thaddeus Berger, Austin Spagnolo, Taylor Atkinson, Meet Pastakia, Zuhoor Yamani, Nicole Ballman, Justin Pavao, Ryan Babbit,
Dannielle Goldman, and Maria Vittoria Elena
Faculty Advisors: Dr. Kunal Mitra, Dept of Biomedical Engineering, Florida Institute of Technology, Dr. Marius Silaghi, Dept of Computer
Science and Cybersecurity, and Mr. David Beavers, Electronic Support Lab, Florida Institute of Technology and Space Coast FabLab
Problem Statement
• Develop an innovative 3D printable prosthetic arm
solution which is strong and life-like in appearance and
function. The device should meet all FDA standards and
be designed for commercialization.
Testing and Results
Acknowledgements
PriMA would like to thank all advisors and supporters to
this project. Special thanks to our advisors, Jennifer
Schlegel, the Kern Entrepreneurial Engineering Network,
Project Based Learning, and the National Science
Foundation, Grant CBET-1403345.
• In order to test, an artificial residual limb was constructed
to test the cooling system inspired by customer feedback.
Principles and Practices
Design
• Solution designed to address all customer concerns
found through the client survey: comfortable and ease
of use while still mimicking the motion of a hand.
• Integrates novel mechanical and sensory features with
the best affordable systems currently on the market at a
low overall cost of about $1,500.
Mechanics
• DC lead screw motors used as low-cost, durable linear
actuators; dual shaft worm-driven gearbox for wrist
control; servo and cable system for thumb control.
• Locking mechanism connects forearm to sleeve. Sleeve
was chosen to use embedded myoelectric sensors and
strength.
• Full range of motion and 50 lb weight limit achieved in
using motor-driven four bar linkages in fingers.
Future Improvements
Software
• Controlled by Arduino Mega
and motor shields.
• Customized supervised-to-
unsupervised machine
learning algorithms allow the
arm to learn gestures after a
brief calibration.
• Stronger materials used for weak points (possible multi-
material design).
• Single circuit board with increased memory.
• Improve battery life.
• Artificial skin covering.
• Increase sensory capabilities.
• Multiple/customized appearance options.
• Standardized, scalable CAD files for manufacturability.
• Reduce sound.
• Four-way wrist motion.
• QIDI Tech FDM printers used
to print parts by designed in
SolidWorks.
• The forearm and hand cover
created using 3D scans.
• Polylactic acid (PLA) chosen
for material properties, cost,
printability, and compatibility
with human skin.
• 3D printing allowed complex
contoured shapes to be
manufactured quickly and
inexpensively. Life-like
curvature made possible using
3D scans.
• Emphasis on consumers – industry and client surveys
were used to develop requirements and determine
necessary functions.
• Software designed minimally to use little storage,
freeing up space for sensory data.
• Used commonly available, affordable electronic and
non-printed components to reduce costs
Electronics
• Force-sensitive resistors in fingers used for touch
sensing.
• Myoelectric sensors in sleeve read muscle tensions as
user input.
• Thermoeletric devices to cool the sleeve, improving
comfortability.
• Temperature sensors in fingers used to determine
dangerously hot or cold objects.
y = -0.1687x2 + 0.0808x + 37
R² = 0.9651
32
33
34
35
36
37
38
0 1 2 3 4 5 6
DegreesinCelcius
Time (in minutes)
Temperature Change of the Residual Arm with and
without the Cooling Device over Time
Normal
Cooling
Device