Design and Construction of a Novel Tactile Sensor for Measuring Contact-Force, Based on Piezoelectric Effect

In this paper, design and construction of a tactile sensor for measuring contact-force is presented. Mechanism of measuring contact-force in this tactile sensor is based on impedance changing of piezoelectric crystal and voltage of different points in circuit as a result of applying force on the crystal. By considering a specific point in the circuit and recording the changes of its voltage, magnitude of applied force can be estimated. Structure of the sensor consists of a disk-shaped piezoelectric crystal that its diameter is 2 cm, its thickness is 2 mm and its resonance frequency is 135 kHz. This crystal is placed in a metal chamber. A spring is on the crystal on which a moving part is installed for applying force. One of the characteristics of the sensor is that its size and shape can be easily tailored to the different applications. By miniaturizing this sensor and using biocompatible materials, it is applicable in different fields of medicine such as minimally invasive surgery (MIS).