This Small Business Innovation Research (SBIR) Phase I project is to determine the feasibility of tactile products for the blind incorporating SRI International's proprietary Electroactive Polymer Artificial Muscle (EPAM) technology with modern electronics and computer technologies. Such products would significantly enhance the educational and vocational opportunities of the blind. The Phase I research objectives include evaluating 3x3 tactile actuator matrices to determine their suitability for expansion to: a) a 36x12 matrix in a dynamic vibratory mode; and b) a full page Braille display in a static mode.
Additional objectives will include determining how this technology can be incorporated in products for blind people that provide access to text documents, graphs, maps, Internet, email, screen displays. The research will involve building and testing tactile stimulator arrays in vibratory and static modes to determine the: 1) capability to support the required amplitudes and forces; 2) dynamic power consumption; 3) required voltages; 4) scalability to the desired matrix size; and 5) manufactureability including cost and automation. The feasibility of high voltage drivers, and the incorporation of other components into the desired package will also be researched. The anticipated results will determine the feasibility of these revolutionary tactile display products for the blind.
The broader impacts/commercial potential of the research is based on providing technology that uses the sense of touch to substitute for, or to augment, vision and hearing. The most effective tactile display has been that in the Optacon, which consisted of a 24x6 array of piezoelectric reeds. Including the pins that contacted the finger, this array had 288 hand-assembled discrete components and 432 hand-wired solder joints on 6 overlapping planes. The result was an expensive to build display that consumed considerable space. EPAM technology promises to reduce the discrete components to a single monolithic polymeric sheet with individually addressable patterned areas, so cost and space are reduced while greatly improving manufactureability. Market segments for blindness products are schools and universities, state departments of rehabilitation, corporations, government agencies, private organizations, and individuals. A goal is to improve the potential commercial value in the blindness field by reducing the price so the individual market segment is larger. The societal impact in the blindness field would be in their increased employment and independence. The research would enhance scientific and technological understanding in the capabilities of the human sense of touch and how to build systems that effectively use it.
The broad goal of the Phase I research was to test the feasibility of a new technology to effectively use the sense of touch to substitute for, or to augment, vision and hearing. Examples are reading systems for the visually impaired, displays for pilots, tactile feedback for touch screens and teleoperator controls, etc. The potential commercial value of success in reaching this goal in the arena of visually impaired alone could be in the range of hundreds of millions of dollars. For visually impaired, the societal impact would be in their increased employment, independence and participation in society. In other fields, the commercial impact could be even greater and the societal impact could be in the augmentation of human capabilities. The intellectual merit of this research is the advancement of scientific and technological understanding in the capabilities of the human sense of touch and how to build cost effective systems that use it. Previous research on the sense of touch has been limited by the technology to produce dynamic tactile displays. The best known dynamic tactile image display is in the Optacon, a reading aid for people who are blind, developed over 40 years ago. The original Optacon development team leader was Dr. James C. Bliss, a Senior Scientist involved in the current Phase 1 project. The Optacon, which is no longer in production, had a 24x6 matrix of tactile stimulators that could produce dynamic tactile images from a 24x6 pixel camera. Long term Optacon users have achieved reading rates and image recognition skills previously thought impossible. Higher definition dynamic tactile displays could enable even greater performance levels. The potentially low cost of the technology under purview of this project would be transformative in making products within the reach of consumers by using the said technology. The specific research conducted was to test the feasibility of SRI's Electroactive Polymer Artificial Muscle (EPAMTM) technology (See Figure 1) to produce dynamic tactile images in products for the visually impaired. With this EPAM technology, an applied voltage increases the polymer area and decreases the thickness proportionally such that total volume is conserved. This basic effect was used in a structure to give out-of-plane actuation of pins whose movement could be felt tactually. A closely spaced two dimensional array of such pins, each driven by an EPAM actuator, can produce dynamic tactile images. In the Phase I of the project, a 3X3 array of EPAM actuators was built that could drive pins over a wide range of frequencies and whose center-to-center spacing could easily be changed (See Figure 2). Testing with this apparatus showed that a simple device using EPAM can produce addressable areas of vibration similar in magnitude to the ones used in the previously successful Optacon products. Some advantages of EPAM technology are: Potentially low cost as it uses simple fabrication techniques (masking and spraying) on a monolithic film to create individually vibrating regions as opposed to assembling individual actuators. High bandwidth of vibration, allowing the use of lower frequency of operation to eliminate nearly all of the audible noise Greater potential for miniaturization for use in portable mobile products.
