Date on Honors Thesis

Spring 5-5-2023


Engineering Physics

Examining Committee Member

Dr. Michael Siebold, Advisor

Examining Committee Member

Dr. James Rogers, Committee Member

Examining Committee Member

Dr. Joshua Ridley, Committee Member


The loss of a limb is a devastating event to an individual on both physical and psychological levels. Despite decades of advancements in medicine, occupational health, and general safety in society, most people know someone or have encountered individuals affected by limb loss. This project created a prosthetic hand designed to aid those individuals. The hand is a predominantly 3D-printed prosthetic hand that includes an individually moving index finger and opposable thumb capable of grasping a full soda can weighing 385 grams (0.85 pounds). Numerous design solutions for the actuation of the fingers and thumb were considered and rejected. Cable actuators and four individually moving fingers with four motors presented too many challenges. Teams of students responsible for mechanics, electrical components, hardware, and CAD modeling cooperated to design a system of two four-bar linkages actuated by four small motors. A mathematical approach was taken to begin the design process, as variables such as force and torque were necessary for selecting motors. One key concern of the movement team was to calculate the coefficient of static friction, µs, applicable to the contact of aluminum and polylactic acid filament. Subsequent calculations yielded the minimum amount of gripping force needed from the fingers and thumb, a required 6.68 N supplied to each side of the can. Free-body diagrams provided the basis for approximating and understanding the forces acting on the object in question. The final design solution complies with two additional important goals for the Project C. L. A. W. S. team: a human-like appearance to lessen the daily psychological impact on the patient caused by the need for a prosthetic and a total manufacturing cost under our designated budget of $2,000. A functioning prototype is expected for delivery at the end of EGR 499 in May 2023.

Additional Author Comments

Honors Thesis completed to fulfill the requirements for HON 438 using research and written works from EGR 499.

Included in

Engineering Commons