Braille cell

Figure 13.2 Concept design of an electronic Braille cell using a CP electrochemical actuator.

Table 13.1 Essential and desirable characteristics of electronic Braille cells...

Figure 13.8 Minimum free stroke required (in <0.5 sec) to meet Braille cell requirements for hypothetical actuators having different moduli (after voltage stimulation) operated against a 1000 N/m spring and for different maximum actuator lengths a) 20 mm b) 30 mm and c) 40 mm.

Figure 23.5 Standard Braille cell consisting of six dots.

Figure 23.8 Assembled Braille cell (a) assembled Braille cell (b) side view (c) top view.

Figure 23.9 Braille tablet made by assembling six modular Braille cells.

As shown in Figure 23.11, two adjacent Braille cells were read by the subjects and the data for two types of recognition rates - Hit Recognition Rate (HRR) and Number Recognition Rate (NRR) - were obtained. HRR denotes the rate at which a subject recognizes movement of the Braille dots and NRR represents whether a subject reads the character correctly as the Braille dots are activated. In the experiments, the HRR and NRR of each subject have been tested when the actuating frequency of the Braille pins was at 15 Hz, which is the normal read out speed of Braille readers. The results of the tests are shown in Table 23.1. In the experiment, the HRR reaches up to about 80 % and the NRR shows a maximum of 41 %. The test results of 80 % for HRR and 40 % for NRR are much better than originally expected. 

Fig. 3 Sheet-type Braille display based on the IPMC actuators (a) photograph of the Braille display, (b) photograph of one Braille cell eomposed of six dots attached with IPMC actuator films, (c) a cross-sectional illustration of one Braille dot The IPMC actuator is driven by an organic transistor. (Reproduced irom Kato et al. 2007)...

Fig. 17 A prototype electronic Braille cell with eight pins individually articulated the linear stroke polymer actuator (Reprinted with permission from Ding et al. (2003). Copyright (2003) Elsevier...

Fig. 20 Photographs of Braille cell using PEDOT/PSS linear actuators...

Fig. 9 (a) Design of the rolled tube actuator based on a bilayer structure of relaxor ferroelectrics embedded between two electrodes, (b) Photograph of the developed prototype Braille cell element with close-up views of the six pins spelling PSU (Reprinted wiA permission (Levard et al. 2012))... 

Fig. 10 A bistable electroactive polymer Braille cell, developed by Pei s group, spells out UCLA (Maffli et al. 2013b)...

Fig. 11 An illustration of a Braille cell based on tubular DA actuators Left, a single actuator right, assembly of actuators in a Braille cell (Reproduced with permission liom Chakraborti et al. 2012)...

---