DESIGN, DEVELOPMENT AND MANUFACTURING OF ROLLED CYLINDRICAL PVDF ACTUATORS FOR BRAILLE DISPLAYS

Open Access
Author:
Diglio, Paul Jonathan
Graduate Program:
Mechanical Engineering
Degree:
Master of Engineering
Document Type:
Master Thesis
Date of Defense:
November 17, 2010
Committee Members:
  • Christopher Rahn, Thesis Advisor
  • Dr Qiming Zhang, Thesis Advisor
Keywords:
  • blocking force
  • Braille display
  • displacement
  • EAP
  • semi-automated manufacturing process
  • rolled actuators
Abstract:
This thesis addresses the challenge of producing miniature and reliable actuators with the requisite displacement and blocking force for tactile Braille displays. Braille displays are an array of characters each with six to eight individually activated pins. Commercially available Braille displays use piezoelectric cantilever beams to actuate the Braille pins, resulting in a bulky, heavy, and expensive device with a limited number of characters. The ElectroActive Polymer EAP actuator introduced in this thesis is in the shape of a long hollow tube and small enough to be placed under the Braille pins, producing a compact, lightweight and scalable design. The condensed size of the devices, material handling, precision required and the large quantity of actuators motivates the development of a semi-automated manufacturing process. The process starts with conductive electrode deposition, lamination to bond the separate films together producing a bi-layer, then cuts and shapes the film, rolls and bonds the bi-layer film into a tube and finally attaches conductive leads. Many actuators are fabricated using this development process and tested for performance and reliability. The results are analyzed and compared to the state of the art.