Spring 2017 Prosthetic Hand: Final Document

The Robot Company | CEO Professor Gary Hill

Executive Summary

By Project Manager | Bianca Esquivel

Project Objective

There are 3 main project objectives that address the problem of the customer being born without a right hand and cater to his preferred recreational activities:

Being able to operate a computer mouse, specifically being able to right click and left click.

  • Ability to scroll is a plus.

Being able to pick up and drink a cup of water.

  • Ability to pick up thin/fragile paper cup is a plus.

Being able to pick up and eat a chips ahoy cookie without breaking the cookie.

  • Ability to pick up and eat a sun-chip without breaking the chip is a plus.

Mission Profile

Mission Profile from Start to Finish:

  • Customer will sit down at a desk in front of a computer with a cup of water and a plate of cookies within the reach of his prosthetic hand
  • The computer will have a game of minesweeper ready to play
  • With the prosthetic hand he will be able to operate the mouse to play minesweeper and reset the game if he should lose or restart the game should he win
  • He will be able to grasp the cup of water within his reach to drink from at his leisure without crushing the cup
  • He will be able to rotate his wrist and grasp a chips ahoy cookie within his reach and eat one at a time at his leisure without crushing the cookie

The Design

  • Complements the measurements of the customer
  • No force sensors are included in the thumb therefore, it isn’t included in the picture
  • Tips of the fingers are equipped with force sensors and rubber tips to help with gripping objects

Project Features

  • Rubber fingertips for better gripping capabilities
  • Force Sensors for a more controlled grip
  • Flex Sensors used to control the grip with the use of the toes
  • PLA Material due to project budget

System Design

By Mission, Systems, and Test Engineer | Chris Bautista

System Block Diagram

Software Block Diagram - Foot

Software Block Diagmram - Hand

Electronics Design

by Electronics and Control Engineer | Forest Nutter

Electronics Custom Parts


Motor Driver Requirements Needed

  • 11v input
  • 5v logic
  • H-bridge included
  • 0.15A output current

Reason for specified IC

  • SMD available
  • Break out board sold from sparkfun for testing
  • Available on DigiKey

Link to requirements

  • L1-2 Motion
    • The prosthetic hand shall have individual motion in at least 2 fingers
  • L2-3 Motors
    • The hand should flex and extend using motors.

Arduino Micro


  • Receive and send data from the xbee
  • Read Analog voltages from the force resistors
  • Control the motor drivers based on inputs from the xbee
  • Control the servo based on inputs from the xbee

Reason for specified MCU

  • Serial Communication
  • 6 Analog Pins
  • 6 Digital Pins
  • 4 PWM Pins
  • 1 Timer
  • 5v logic, but also accepts 3.3v logic
    • Useful because xbee is a 3.3v device
  • Available from last semester
Motor Driver Used

Arduino Micro

Firmware: Foot PCB Code

Firmware: Hand PCB Code

Mode Chooser Flow Chart

Motor Control Flow Chart

Servo Positioning Flow Chart

Xbee Flow Chart

Breadboarded Xbee Circuit

Breadboarded Flex Sensor Circuit

Hand PCB Schematic

Foot PCB Schematic

Hand and Arm PCB Layout

Foot PCB Layout

Hardware Design

by Manufacturing and Design Engineer | David Mendoza

Link to Final Prosthetic Hand Palm Design Blog Post:

Prosthetic Hand Palm Design

Link to Final Prosthetic Hand Fingers Design Blog Post:

Prosthetic Hand Fingers Design

Verification Tests

by Mission, Systems, and Test Engineer | Chris Bautista

Link to Verification & Validation Report – Prosthetic Hand:

V&V Prosthetic Hand

System Resource Reports

by Mission, Systems, and Test Engineer | Chris Bautista

Power Allocation

Mass Allocation

Cost Allocation


by Project Manager | Bianca Esquivel

Project Resources

Project Video: Prosthetic Limb 2017 Project Video

CDR PowerPoint: Prosthetic Hand CDR PPT

PDR PowerPoint: Prosthetic Hand PDR PPT

Project Libre & Excel Burndown: Prosthetic Limb Schedule & Burndown

Verification & Validation Report: V&V Prosthetic Hand

Solidworks Files: Mechanical Blog Post 1Mechanical Blog Post 2

Fritzing Files: Electrical Blog Post 1Electrical Blog Post 2Electrical Blog Post 3

Eagle CAD Files: Electrical Blog Post 4

Arduino Code: Software Blog Post

Bill of Materials: Prosthetic Hand Reimbursement Form

The Entire 400D Prosthetic Limb Folder: Prosthetic Limb 2017 Group Folder