State Key Laboratory of Advanced Materials for Smart Sensing, GRINM Group Co. Ltd, Beijing 100088, People's Republic of China.
GRIMAT Engineering Institute Co., LtD, Beijing 101407, People's Republic of China.
Nanotechnology. 2021 Feb 26;32(9):095106. doi: 10.1088/1361-6528/abca5f.
Glaucoma is the second leading cause of blindness in the world. Intraocular pressure (IOP) is a primary indicator of glaucoma which can be measured for the treatment of the disease. This paper presents a piezo-resistive principle pressure sensor to monitor IOP continuously and non-invasively. The sensor is designed based on the Wheatstone bridge circuit and fabricated by the spray-coating method. The hybrid nanomaterials of graphene and carbon nanotubes are introduced as sensing layers which are embedded inside the soft contact lens substrate composed of flexible polydimethyl siloxane (PDMS) and parylene. The sensing performance is discussed followed by a brief description of our sensor design and fabrication. Tests on a PDMS eyeball model indicate that it has a high sensitivity of 36.01 μV mmHg. Also, the frequency response and the ability to track dynamic pressure change cycles are demonstrated in normal IOP variation range from 9 to 34 mmHg. It shows good repeatability and linearity, and can accurately track fluctuating IOP. Thus, this sensor, with its ease of fabrication and simple design, as well as allowance for continuous pressure measurement, offers a promising approach for IOP monitoring in clinical diagnosis of glaucoma.
青光眼是全球第二大致盲原因。眼内压（IOP）是青光眼的主要指标，可以通过测量来治疗这种疾病。本文提出了一种基于压阻原理的压力传感器，用于连续、非侵入式地监测 IOP。该传感器基于惠斯通电桥电路设计，采用喷涂法制造。混合纳米材料石墨烯和碳纳米管被引入作为传感层，嵌入由柔性聚二甲基硅氧烷（PDMS）和聚对二甲苯组成的软接触透镜基底内。本文讨论了传感性能，并简要描述了传感器的设计和制造。在 PDMS 眼球模型上的测试表明，它具有 36.01 μV mmHg 的高灵敏度。此外，还展示了在正常 IOP 变化范围为 9 至 34 mmHg 内的频率响应和跟踪动态压力变化循环的能力。该传感器具有良好的重复性和线性度，能够准确跟踪波动的 IOP。因此，这种传感器具有易于制造、设计简单以及允许连续压力测量的优点，为青光眼的临床诊断中的 IOP 监测提供了一种有前途的方法。
