This study aims to investigate (1) the availability of learning facilities for distance learning (or online learning), (2) the ability of students and teachers to utilize the learning facilities, and (3) how distance learning activities take place at public or private vocational high schools, specifically whether it is perceived to be more interesting than ordinary learning. This study used a survey method to obtain data and a quantitative descriptive method to analyze the data. The type of data in this study was primary based on the responses of respondents or individuals from groups representing the population of public and private vocational high schools, especially in the Electrical Engineering Clusters in the entire areas of West Java. The results revealed that online learning has been carried out in many public and private vocational high schools in West Java. This study indicates that the availability of online learning facilities, the utilization of facilities, and the online learning process in public vocational high schools were better than those in private vocational high schools. In general, students of both public and private vocational high schools stated that online learning is not more interesting than ordinary learning, although most of them can understand the lessons taught and they were given an opportunity by their teachers to actively participate during the learning process.

In this study, we present a comprehensive review of polymer-based microelectromechanical systems (MEMS) electromagnetic (EM) actuators and their implementation in the biomedical engineering field. The purpose of this review is to provide a comprehensive summary on the latest development of electromagnetically driven microactuators for biomedical application that is focused on the movable structure development made of polymers. The discussion does not only focus on the polymeric material part itself, but also covers the basic mechanism of the mechanical actuation, the state of the art of the membrane development and its application. In this review, a clear description about the scheme used to drive the micro-actuators, the concept of mechanical deformation of the movable magnetic membrane and its interaction with actuator system are described in detail. Some comparisons are made to scrutinize the advantages and disadvantages of electromagnetic MEMS actuator performance. The previous studies and explanations on the technology used to fabricate the polymer-based membrane component of the electromagnetically driven microactuators system are presented. The study on the materials and the synthesis method implemented during the fabrication process for the development of the actuators are also briefly described in this review. Furthermore, potential applications of polymer-based MEMS EM actuators in the biomedical field are also described. It is concluded that much progress has been made in the material development of the actuator. The technology trend has moved from the use of bulk magnetic material to using magnetic polymer composites. The future benefits of these compact flexible material employments will offer a wide range of potential implementation of polymer composites in wearable and portable biomedical device applications.

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Micro Electro Mechanical System (MEMS) energy harvester's research interests have been increasing rapidly, indicating that the topic has given significant contributions to the sustainable development of energy alternatives. Although many research activities have been conducted and reported since several years ago, only limited efforts have been made to analyze the research's impact in this area. In this paper, we report a bibliometric analysis on the research progress in MEMS for energy harvester. VOSviewer software is used to support the analyst that includes the distributions of the publication journals, authors, affiliations and the highly cited papers reporting the progress as well as the frequency of keywords and their relationships found in the search engine. The analysis is mainly aimed to identify the research map based on publication reports. 1772 papers were initially identified and summarized based on the analysis on three focused mainstream research topics in MEMS for alternative energy, such as MEMS energy harvester, power harvesting and energy scavenging, other term analogies to MEMS such as micromachines and microsystem were included in the analysis parameter. As a result, it is found that the study on the MEMS energy harvester is mostly categorized in the engineering field, while China has been conducting the most projects. The Journal MEMS and Journal of Micromechanics and Microengineering have been the most journals publishing reports on MEMS energy harvester's research progress. Based on these analyses, some potential issues in future MEMS energy harvester research have been identified, including the contributions of new materials, the MEMS new structure's involvement, and the optimization of the vibration concepts and principles of MEMS energy harvester. These analyses would give an overview on the progress of the development and improvement in MEMS energy harvester and give a proper guideline for future MEMS research in the energy field.

A turbidity telemetry system for COVID-19 pandemic situations using nRF24L01+transceiver and SEN0189 water turbidity sensor-based microcontroller has been successfuly  developed.. The method used to characterize the sensor is by comparing sensor output voltages with the value of water turbidity. Turbid water used was created by adding distilled water with a concentration of sediment obtained from the filtered sediment with less than 60 μm in diameter. Data transmission performance for various transmit power was done by calculating the error percentages by comparing the number of messages sent by transmitter and received by receiver. The transmit power settings were 0, -6, -12, and 18 dBm and variations in the distance of data transmission from 10 to 80 m. The test results show that the water turbidity sensor has a good measurement range in measuring turbidity of water from 1.873 to 3500 NTU. Higher concentrations of sediment and turbidity of the water made the sensor output voltage decrease. There was a decrease in output voltage in the value, namely -0.0006 in turbidity sensor sensitivity. The results also show an increase in error percentages as the distance of data transmission increases, while the bigger the transmit power is used for data transmission, the smaller the percentage of errors occurs.