A New Approach in Design and Operating Principle of Silicone Tactile Sensor

Problem statement: Research and development in tactile sensor are escalating due to the fact that advanced robot needs to interact with surrounding environments which is very complex, dynamic, uncontrolled and difficult to perceive reliably. Recent research has been focusing in development of new tactile sensor that takes advantage of advances in materials, Micro-Electromechanical Systems (MEMS) and semiconductor technology. To date, several basic sensing principles are commonly used in tactile sensor such as capacitive sensor, piezoelectric sensor, inductive sensor, opto-electrical and piezo-resistive sensor. However they are still lack of sensitivity and low dynamic range in sensing the changes of forces in 3 axes and not durable enough to perform in various working environments. Approach: Three different designs of optical tactile sensor was proposed and analyzed. The overall design of the test-rig of the system was presented. The working principle was based on the deformation of the silicone tactile sensor. The deformation image will be transferred through high quality medical fiberscope and will be recorded using a CCD camera. The image will be stored in a computer for further analysis to relate the image with the given forces. These data can be used to control a robotic gripper so that it can perform gently and precisely like human tactile sensing capability but with greater strength and durability in various working environments. Results: The sensor had been designed and an experimental test rig was developed. Initial experiment was carried out to check the potential of this technique. Based on results, there is almost a linear relationship between the forces and the deformation of the tactile sensor. The amount of deformation is calculated based on the analyzed image data. Conclusion: The results of the experiment gave a convincing idea and provide a ground for further research to enhance this system to be an alternative tactile sensor in future.