ABSTRACT
Microelectromechanical systems (MEMS) enable many modern-day technologies, including actuators, motion sensors, drug delivery systems, projection displays, etc. Currently, MEMS fabrication techniques are primarily based on silicon micromachining processes, resulting in rigid and low aspect ratio structures. In this study, we report on the discovery of MEMS functionality in fibres, thereby opening a path towards flexible, high-aspect ratio, and textile MEMS. The method used for generating these MEMS fibres leverages a preform-to-fibre thermal drawing process, in which the MEMS architecture and materials are embedded into a preform and drawn into kilometers of microstructured multimaterial fibre devices. The fibre MEMS functionality is enabled by an electrostrictive P(VDF-TrFE-CFE) ferrorelaxor terpolymer layer running the entire length of the fibre. Several modes of operation are investigated, including thickness-mode actuation with over 8% strain at 25 MV m-1, bending-mode actuation due to asymmetric positioning of the electrostrictive layer, and resonant fibre vibration modes tunable under AC-driving conditions.
ABSTRACT
Ultrasound transducers have many important applications in medical, industrial, and environmental settings. Large-active-area piezoelectric fibers are presented here, which can be woven into extended and flexible ultrasound transducing fabrics. This work opens significant opportunities for large-area, flexible and adjustable acoustic emission and sensing for a variety of emerging applications.
Subject(s)
Acoustics/instrumentation , Electricity , TransducersABSTRACT
In the past decade, novel fiber structures and material compositions have led to the introduction of new diagnostic and therapeutic tools. We review the structure, the material composition and the fabrication processes behind these novel fiber systems. Because of their structural flexibility, their compatibility with endoscopic appliances and their efficiency in laser delivery, these fiber systems have greatly extended the reach of a wide range of surgical lasers in minimally invasive procedures. Much research in novel fiber-optics delivery systems has been focused on the accommodation of higher optical powers and the extension to a broader wavelength range. Until recently, CO2 laser surgery, renowned for its precision and efficiency, was limited to open surgeries by the lack of delivery fibers. Hollow-core photonic bandgap fibers are assessed for their ability to transmit CO2 laser at surgical power level and for their applications in a range of clinical areas. Current fiber-delivery technologies for a number of laser surgery modalities and wavelengths are compared.
