Preliminary Description of the evaluation results:

Qualitative evaluation techniques: Subjective feedback from independent users.

The finished prototype performance will be evaluated by testing the performance using independent user feedback and comparing it with intended results.

To elaborate; our aim is to induce an experience of different levels of  friction on the T-PaD surface and we would ask the user for feedback on what he/she experienced when using the surface.

Sketch for the Prototype:

(Still waiting on components so heres a reference of how things should resemble - will repost our own results once the components arrive.)

The following pictures are only an illustration to give an idea of how the completed parts would appear:

A Picture of the completed TPAD

A Picture of the Completed Circuit Board.

A Picture of the TPad Fire Assembly

Development schedule for the prototype is held until the components arrive.

Reference Papers for the Project:

"Squeeze Film Effect for the Design of an Ultrasonic Tactile Plate" - M´elisande Biet, Fr´ed´eric Giraud, Member, IEEE, and Betty Lemaire-Semail, Member, IEEE.

"T-PaD: Tactile Pattern Display through Variable Friction Reduction" - Laura Winfield, John Glassmire, J. Edward Colgate, Michael Peshkin.

"ShiverPaD: A Glass Haptic Surface That Produces Shear Force on a Bare Finger" - Erik C. Chubb, Student Member, IEEE, J. Edward Colgate, Member, IEEE and Michael A. Peshkin, Member, IEEE.

Abstract:

All most all commercially available touch displays have no texture to touch. Introducing an element of texture in such displays would greatly enhance the experience of using the device. However most tactile displays currently built rely on pin based arrays which cannot be easily integrated into normal touch screens. In this project we reconstruct a haptic display for creating texture sensation through variations in surface friction using the squeeze film effect between a plate and a finger. The plate is actuated using piezoelectric ceramics. Ultrasonic vibrations are thus produced and are capable of generating the squeeze film effect. This enables us to simulate variable friction on the surface of the display plate. The base device being used is a Kindle Fire 1st Generation, on top which a glass plate is placed which is the surface that is vibrated to produce the squeeze film effect.

Project Topic:

"Reconstructing the TPAD FIRE an open-source surface haptics device."

Project Group Members:

Arjun Rajasekar, Masters Student at Drexel University in the ECE Department.

Mengchen Zhang, Masters Student at Drexel University in the ECE Department.

Project Guide:

Dr.Yon Vissel, Assistant Professor at Drexel University in the ECE Department.

Project Description:

The aim of the project is to reconstruct the TPAD FIRE, a variable friction surface combined with a Kindle Fire. The Device has been designed by the Neuroscience and Robotics Lab at the North Western University.

Here is a link to the website of TPAD TABLET PROJECT; the main source of information for building the device, that will be followed during the course of this project.