A wearable omnidirectional inertial switch of security detection for the elderly

• Published in: Microsystem technologies : sensors, actuators, systems integration actuators, systems integration, 2022-09, Vol.28 (9), p.2011-2021
• Main Authors: Du, Liqun, Guo, Bingjiang, Dong, Yakun, Kong, Dejian, Zhao, Jian, Liu, Xuqiang, Liu, Junshan
• Format: Article
• Language: English
• Subjects: Electronics and Microelectronics; Engineering; Instrumentation; Mechanical Engineering; Nanotechnology; Technical Paper
• ISSN: 0946-7076; 1432-1858
• DOI: 10.1007/s00542-022-05339-z

For the purpose of monitoring security for the elderly in daily life, a novel space-omnidirectional wearable inertial switch was designed, fabricated and tested for fall detection system in this paper. Omnidirectional dynamic response of the inertial switch was simulated and analyzed using ANSYS software. The simulation results indicated that the inertial switch can be closed in the omnidirectional space at an acceleration of 4.24 g, the response time of the switch is less than 2.6 ms, and the contact time of the switch is more than 200 μs. Besides, the inertial switch was fabricated using UV-LIGA multilayer photolithography and precision micro electroforming technologies, and the dynamic test of the switch was carried out by the drop hammer experiment. The test results showed that the inertial switch can be closed at an acceleration of more than 5 g. Meanwhile, all contact time is more than 110 μs and the longest is 366 μs, which can meet the application requirements.