Creating a 3D Printed Hand Prosthetic Georgia Donaldson Mr. Spangler Whitefish High School Advanced Chemistry

Introduction My goal for this project is to develop a hand prosthetic for a candidate in the Flathead Valley that will be based off of the Robohand.

Robohand ●Founders: Ivan (habitant of America) and Richard (habitant of South Africa) o Richard cut off his right hand fingers in a woodworking accident o Wanted to find a cheaper prosthetic ●The company MakerBot donated two 3D printers ●Richard and Ivan communicated through the internet and printing prototypes while the other was asleep ●they created a cheaper hand prosthetic using 3D printing ●RoboHand is still inventing today

Backround ●Candidates o Symbrachydactyly: “short joined fingers” o finger amputated hands ●Main 3D printing material o ABS (acrylonitrile butadiene styrene)  HIPS (dissolves in limonene, a liquid hydrocarbon) o PLA (polylactic acid). ●Regular upper limb prosthetic: $3,000-$30,000 ●Robohand: $56-$500 ●MakerBot Printer: $2,000-$6,000

Mechanics ●As the patient's wrist bends forward, the fingers curl ●Simple wiring through the hand creates tension ●Rubber string in the fingers creates resistance ● All fingers close and extend together

Procedure ●Cuff and Gauntlet Orthoplastic: Orfit o 1/8in (3.2mm) thickness o Perforation o Maximum resistance to stretch ●Patient o Missing fingers and pinky knuckle

The Frame ●Print and scale the frame ●Thread two of the fingers and thumb with bungee cord and nylon cable then secure with black thread and superglue ●Attach fingers to knuckle block and share the bungee cord with the neighboring finger ●screw in the wrist joint and secure the frame with screws and nuts

Cuff and Gauntlet ●Mold orthoplastic and secure to the frame ●Heat cable blocks and super glue to the top of the orthoplastic ●Thread nylon cables and secure with a brass anchor

The Finished Product Secured with velcro straps

Conclusion 3D printing is changing the field of prosthetics. Many open source blogs are taking advantage of its cheap innovative potential and letting the public role with the design. 3D printed prosthetics are also great for kids due to constant outgrowth of these mechanisms. 3D printing would benefit the general public and make prosthetics more accessible/ affordable. Also in this project, I have learned about the different polymers implemented into these new prosthetics and how the mechanics of the hand can be tweaked to fit the needs of the consumer.

Improvements ●Wrist movement ●Fixed wrist angle ●Finger grip ●Types of joint wiring material ●Types of orthoplastic

References ● "The Journey." Robohand. N.p., n.d. Web. 14 Jan ● "MakerBot Store." MakerBot. N.p., n.d. Web. 14 Jan ● "Product Overview." Robohand USA. N.p., n.d. Web. 14 Jan ● 7/9/2010. Embryology Congenital Hand (n.d.): n. pag. Web. ● "Upper Limb Prosthetics." Enabling The Future. N.p., 26 May Web. 14 Jan

Acknowledgements Thank you: Denise Zander John Ruonavaara Ty Esham Without your efforts my project would not be possible