1. Testing the Tactile Perception of Human Fingers The Dynamic Tactile Tablet (DTT) Chamiere Greenaway & Eric Balfour

2. Motivation To make it easier for blind people to access graphical information from a computer www.abtim.comenablemart.com www.google.com

3. Tactile Sense Tactile Sense is how we perceive something by touching. The human finger is able to distinguish a dot that is 1mm in diameter and height. a b c Braille Specifications a - ~1.3 mm b - ~2.5 mm c - ~2.5 mm dot height: ~0.5 mm Schematic of a Braille Cell Module. Picture of the Talking Tactile Tablet.

4. To create a tactile interface from Polydimethylsiloxane (PDMS) To test tactile interfaces to find the optimum parameters for: the height the diameter the spacing of raised dots that will give us the best results for the tactile perception of human fingers.

5. Experimental Setup 1) Make mask from modeling clay 2) Pour liquid PDMS over the mask 3) Cure PDMS/Clay assembly at 70°C (PDMS hardens) 4) PDMS is peeled off the mask (inverted structure of initial mask)

6. Preliminary Results We created three masks out of Modeling Clay for the testing of : Height of Dots: Spacing of Dots: Diameter of Dots:

7. Preliminary Results

8. Conclusions & Outlook The Modeling Clay can be used as a mask. The Modeling Clay is compatible with the PDMS. PDMS can be used to create a testing surface. In the future, perform measurements to find the optimum height, diameter and spacing.

9. Acknowledgements Professor Ilona Kretzschmar Dr. Sat Battacharya & MSKCC Chemical Engineering Students & Staff @ CCNY Harlem Children Society