High quality factor parylene-based intraocular pressure sensor

A new concept of the intraocular pressure (IOP) sensor design and its implantation approach are presented in this paper. A parylene-based sensing part with about 30 μm in thickness was fabricated, and then integrated with an implantation tube attached to sensor's backside pressure access hole. During the implantation, only the implantation tube was implanted into the anterior chamber to fulfill minimally invasive implantation. The IOP sensor membrane is thin and flexible so that it can attach to the cornea. Because the sensing area was exposed outside to the air all the time, the quality factor can be kept at 27-30 to maintain the sensing distance during the whole testing pressure range. The sensitivity is obtained as high as 542 ppm/mmHg while the responsivity is about 205 kHz/mmHg, which is suitable for biomedical applications.