부산대학교 도서관

Long-term implantable pressure monitoring is a key clinical parameter bringing a lot to clinicians by helping them treating many chronical diseases (e.g. glaucoma, hydrocephalus or heart failure). However for decades and up to now, most of the implantable sensors exhibited poor technological and clinical success due to the long-term biocompatibility constraints of the transducing part. The prime novelty of this paper is to propose a functional implantable MEMS pressure sensor with a bulk-micromachined titanium (Ti) transducer. Thanks to its small size, the active part of the sensor is thought versatile enough to be integrated in an active implantable device for measuring various intracorporal pressures. The transducer is made out of grade 1 Ti, which is one of the metalic materials of choice to insure long-term biocompatibility and has been proved to be a reliable material in the implantable industry. The uniqueness of the proposed sensor comes from its micromachining. The transducer, including a bulk titanium membrane, has been obtained through subtractive machining techniques benefiting from the extensive research experience on silicon MEMS. This Ti-based technology avoids the use of additionnal costly, complex and bulky encapsulation step to get a biocompatible device, thus enabling higher miniaturization level of implantable devices and lower rate of long term drift risks thanks to its monolithic architecture. The presented Ti MEMS sensor exhibits 1 fF mmHg−1 sensitivity within a clinically relevant pressure range of 0–300 mmHg, which is compatible with off the shelf low-power readout electronics. [ABSTRACT FROM AUTHOR]