TY - JOUR AB - The paper presents the results of numerical and experimental investigation of cylindrical piezoelectric actuator used for achieving independent three degrees of freedom oscillations of the contact point. The design of actuator based on a hollow piezoelectric cylinder mounted on a metal rod. The piezoceramic cylinder has a radial polarization and special configuration of the electrodes that cover inner and outer surface of the cylinder. The main advantage of actuator's design is that solid metallic rod operates as a part of inner electrode of the cylinder and a stator of actuator. The geometry of piezoelectric actuator was adopted to reach resonance of oscillations for the first longitudinal mode and the third flexural mode at same frequency. The actuator is designed to move positioned object through contact point which is located on the top of the rod. The optimal topology of electrodes was found to achieve longitudinal and flexural oscillations of the actuator in two perpendicular planes. Three degrees of freedom of the positioning object can be achieved and control of the system can be implemented by applying different excitation schemes and regimes. The numerical simulation and experimental study of piezoelectric actuator was performed. Impedance of actuator was analyzed under different excitation regimes. The results of numerical modeling and experimental study were compared. Recommendations for the further development of this type of actuator are given. AU - Lucinskis, Raimundas AU - Mazeika, Dalius AU - Hemsel, Tobias AU - Bansevicius, Ramutis ID - 9767 IS - 1 JF - AIP Conference Proceedings KW - dielectric polarisation KW - piezoceramics KW - piezoelectric actuators TI - Multi-DOF cylindrical piezoelectric actuator with radial polarization VL - 1433 ER - TY - CONF AB - In neurosurgery, delineation of tumor boundaries during resection of brain tumors is of substantial relevance. During operation distinction between tumor and healthy tissue rely on the abilities of the surgeon based on visual and tactile differentiation. In this paper a high sensitivity actuator-sensor system using a piezoelectric bimorph is presented. Frequency shift and transfer function of the bimorphpsilas voltages are detected and evaluated. Sensorpsilas sensitivity is evaluated using two frequency controls strategies: A phase-locked loop (PLL) and a self-oscillating circuit. Results of measurements conducted on gel-phantoms are presented and discussed. AU - Uribe, David Oliva AU - Stroop, Ralf AU - Hemsel, Tobias AU - Wallaschek, Jörg ID - 9576 KW - biomedical measurement KW - brain KW - cancer KW - neurophysiology KW - phantoms KW - phase locked loops KW - piezoelectric actuators KW - surgery KW - tactile sensors KW - transfer functions KW - tumours KW - PLL KW - biomedical tissue differentiation system KW - brain tumor resection KW - frequency control KW - frequency shift KW - gel-phantom KW - high sensitivity actuator-sensor system KW - neurosurgery KW - phase-locked loop KW - piezoelectric actuators KW - piezoelectric bimorph KW - self-oscillating circuit KW - sensor sensitivity KW - tactile differentiation KW - tactile sensor system KW - transfer function KW - tumor boundary KW - visual differentiation KW - Biomedical measurements KW - Circuits KW - Frequency control KW - Neoplasms KW - Neurosurgery KW - Phase locked loops KW - Piezoelectric actuators KW - Surges KW - Transfer functions KW - Voltage SN - 1075-6787 T2 - Frequency Control Symposium, 2008 IEEE International TI - Development of a biomedical tissue differentiation system using piezoelectric actuators ER -