Advances in Bio-Microelectromechanical System-Based Sensors for Next-Generation Healthcare Applications

Abstract

Microelectromechanical system (MEMS)-based sensors have become essential in various fields, including healthcare, automotive, and industrial applications. These sensors integrate mechanical structures and electronics on a single chip, allowing precise, compact, and efficient measurements of parameters like pressure, force, acceleration, and chemical reactions. In this context, this review article presents the essential role of MEMS sensors in healthcare applications. In healthcare, MEMS sensors are widely used for monitoring vital signs, detecting glucose levels, managing cardiovascular and intracranial pressure, and enhancing drug delivery systems. They are also key in tactile sensing during surgeries and in improving neuromuscular monitoring through electromyography (EMG). Despite their advantages, such as small size, low energy consumption, and high performance, MEMS sensors face challenges like sensitivity drift, durability concerns, and long-term calibration stability. This article addresses these limitations and highlights ongoing advancements aimed at improving sensor accuracy, energy efficiency, and adaptability to diverse environments. By examining current trends and innovations, this review provides insights into how MEMS technology is driving breakthroughs in biomedical research, early cancer diagnosis, and bioimaging treatment. We have discussed inertial sensors, MEMS-based glucose sensors, intraocular pressure (IOP) sensors, intracranial pressure sensors, cardiovascular pressure sensors, tactile sensors, and smart inhalers. In addition, we have explored recent advancements in MEMS technologies applied to healthcare, particularly in microfluidic MEMS chips and brain-machine interfaces, with a focus on developments from the last five years. Future research directions focus on enhancing the flexibility, reliability, and energy efficiency of MEMS sensors, positioning them as key components in the next generation of healthcare and medical devices.

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(a) Schematic of a piezoresistive-based absolute pressure sensor; (b) optical image of a pressure sensor combined with an “H”-shaped silicon resonator; reproduced from ref with permission from MDPI, Copyright 2020. (c) Schematic diagram of a piezoelectric pressure sensor with an SEM image of the cross-section of an aluminum nitride film placed on a polyester network; reproduced from ref with permission from the American Institute of Physics, Copyright 2006. (d) Variation in resistance with applied pressure; reproduced from ref with permission from MDPI, Copyright 2020. (e) Schematic of a biodegradable pressure sensor. (f) Optical microscopy image of the pressure sensor; reproduced from ref with permission from Springer Nature, Copyright 2016.

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(a) Microelectrode on polyimide; (b) temperature responses in the cell medium; (c) pressure variations along with neuronal temperature were analyzed over a period of 15 days. Reproduced from ref with permission from Elsevier, Copyright 2019.

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(a) Bronchoscopy process using a medical catheter; (b) implantable device for monitoring arterial pulses; (c) catheter with sensors in a lung phantom for bilateral sensing; (d) pressure vs. time plots from two pressure sensors in the left lobar division of the lung; (e) pressure vs. time plots of signals detected on the skin and above the carotid artery; (f) water flow-induced pressure response observed via an implantable sensor; (g) implantable device positioned in the radial artery; (h) radial pressure signals verified using an NFC-enabled mobile phone. Reproduced from ref with permission from the American Chemical Society, Copyright 2022.

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Passive and active time-released devices: (a) active microchip designed using conductive substrate materials; (b) passive microchip containing reservoirs etched into the substrate; reproduced from ref with permission from Taylor & Francis, Copyright 2014; (c) silicon needle fabricated through wet etching; reproduced from ref with permission from Elsevier, Copyright 2004; (d) microneedle formed using molding and wet etching techniques; reproduced from ref with permission from Springer Nature, Copyright 2013.

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(a) Simulation analysis of H₂O₂ distribution inside the microfluidic chip; (b) contours showing wall shear stress circulation in a capillary; (c) simulation study of moderately stiff beads with specified shear elastic modulus; (d) graphical representation of red blood cells (RBCs) passing through a narrow microchannel. Reproduced from ref with permission from Elsevier, Copyright 2022.

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(a) Schematic diagram of a MEMS scanner using an AVC actuator; (b) scanner mirror fabricated on single-crystal silicon with two vertical-comb structures; (c) schematic diagram of dual-axis confocal microscopy integrated with a MEMS scanner. Reproduced from ref with permission from MDPI, Copyright 2020.

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(a) PDMS-based microfluidic MEMS device for the detection of specific mutations in HCC ctDNA; reproduced from ref with permission from Springer Nature, Copyright 2024. (b) Working principle of a shear-horizontal surface acoustic wave (SH-SAW) sensor; reproduced from ref with permission from Nature, Copyright 2020.

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(a) Nanomaterial-based MEAs for in vitro bidirectional BCI; reproduced from ref with permission from Springer-Nature, Copyright 2023, (b) portable earphone capable of real-time EEG analysis; (c) in-ear cap sensor containing nanoparticles along with memory foam; (d) hydrogel–elastomer neural interfaces; (e) the interface implanted with MRI scanner, optical microscopy, and electrical recording integrated with MR imaging. Reproduced from ref with permission from John Wiley and Sons, Copyright 2023.