Highlights• A wireless sensor node architecture composed from energy harvesting transducer, energy accumulating capacitor, sensors, microcontroller and RF link is proposed and fabricated. • The elaborated algorithm and the created detector could reach no more than 100-150 nA current consumption. • The created wireless sensor energy harvester prototype satisfies the energy needs for sensors and is capable of transmitting the information at the distance of 20 metres. • For cutting tool performance evaluation the limitary moment, when cutting tool starts manufacturing inappropriate quality parts, is defined experimentally and statistically. • The created device opens a way for wireless sensors networks in manufacturing technologies. Graphical abstractVitaeVytautas Ostasevicius graduated from Kaunas University of Technologyengineer mechanic in 1971, doctor of sciencies in 1974, doctor habilitus in 1988. and in industry. His research focuses on electronic system efficiency, energy harvesting, low power management and wireless smart sensors. Mindaugas Cepenas graduated from KaunasUniversity of Technology (KTU) in 2012 with Master's degree in Electrical engineering. Currently, PhD study in Electrical and Electronics Department of Electronics Engineering studies KTU. Research areas -interactive design of microprocessor systems and low-power wireless networks. Laura Kizauskiene is an associate professor at the Department of Computers, and researcher at the Real-time Computer Systems Centre at Kaunas University of Technology. She has gained doctors' degree in Technology Science in 2009. Her main research interests are multi-agent systems, artificial intelligence, wireless sensor networks, embedded real time systems and smart environments. Since 2007, she has been working at Kaunas University of Technology and has participated in several research projects, developing smart house and sensor network technologies. Virginija Gyliene received her License Professional degree (Conception and Fabrication assisted by Computers) from the University of Maine (France) in 2001. She gained a Master degree in Manufacturing Engineering in 2002 and Ph. D. degree in 2007 from KaunasUniversity of Technology. Now, she is the Lecturer in the same University and her research field is numerical and experimental study of cutting processes. AbstractThis paper presents a method of cutting tool vibration energy harvesting for wireless applications, the created devices and the results of the accomplished experiments. The proposed high frequency piezo generator assures energy harvesting, accumulation and appropriateness for wireless sensors applications. The proposed architecture composed from energy harvesting transducer, energy accumulating capacitor, sensors, microcontroller and RF link opens a way for wireless sensors networks in manufacturing technologies providing the effective integration of information, delivered by sensors of different nature, to achieve a wholesome description of the status of the monitored process. The elaborated algorithm a...

An effective system for monitoring the wear of the machine tool inserts could significantly contribute to saving costs in manufacturing. One of the most recent and popular of effective monitoring methods revolves around the use of sensing technologies for indirect estimation of tool wear. The sensory information is difficult to collect from machine tools due to the extremely poor signal-to-noise ratio of the relevant tool wear-related information because the milling operation is of interrupted nature since the work piece is in contact with the tool edge several times per second. Another issue is the varying thickness of the chip during the penetration of the work piece. Yet, many challenges still impede the practical application of this method for industrial environment. Therefore, the paper presents a method that could solve these challenges especially in industrial environment. The proposed selfpowered wireless sensor node is integrated in the structure of the cutting tool. The voltage generated from the cutting tool vibrations of the harvester exponentially rises when the capacitor is fully charged and wireless signal sent to the receiver. As the intensity of energy accumulation depends on the state of the cutting tool wear, it indicates and detects the tool condition. The proposed technique could be useful for the identification of the cutting tool quality and the relative tool-work piece position. The information about the variation of tool wear is beneficial for helping the manufacturers to control the cutting process, to minimize the product cost as well as to improve the machining quality and efficiency.

The objective of this study was to determine the effects of teeth bleaching on the tensile bond strength of metal brackets bonded with light-curing adhesive system to the human enamel. 40 recently extracted human permanent molars were used for the study. The mesial buccal surface of each tooth was used as a control group and the distal buccal surface was used as an experimental group. Control group surfaces were not submitted to bleaching, while experimental group surfaces were bleached with in-office bleaching material containing 35% hydrogen peroxide. 30 days after the bleaching, identical premolar metal brackets were bonded to each surface using light-curing adhesive. Both groups were submitted to a tension test, using a universal machine. The tensile bond strength of brackets bonded to the bleached enamel was 15% lower than that of brackets bonded to the unbleached enamel. After debonding, more adhesive was left on the bracket base in experimental group than in the control group. The conclusion of this study was that bleaching with an in-office bleaching material containing 35% hydrogen peroxide reduced the tensile bond strength of orthodontic bracket adhesive to the enamel surface.

A novel design of a multiple degrees of freedom (multi-DOF) piezoelectric ultrasonic motor (USM) is presented in the paper. The main idea of the motor design is to combine the magnetic sphere type rotor and two oppositely placed ring-shaped piezoelectric actuators into one mechanism. Such a structure increases impact force and allows rotation of the sphere with higher torque. The main purpose of USM development was to design a motor for attitude control systems used in small satellites. A permanent magnetic sphere with a magnetic dipole is used for orientation and positioning when the sphere is rotated to the desired position and the magnetic field synchronizes with the Earth’s magnetic dipole. Also, the proposed motor can be installed and used for robotic systems, laser beam manipulation, etc. The system has a minimal number of components, small weight, and high reliability. Numerical simulation and experimental studies were used to verify the operating principles of the USM. Numerical simulation of a piezoelectric actuator was used to perform modal frequency and harmonic response analysis. Experimental studies were performed to measure both mechanical and electrical characteristics of the piezoelectric motor.

No abstract