Recent Progress of Miniature MEMS Pressure Sensors

Abstract

Miniature Microelectromechanical Systems (MEMS) pressure sensors possess various merits, such as low power consumption, being lightweight, having a small volume, accurate measurement in a space-limited region, low cost, little influence on the objects being detected. Accurate blood pressure has been frequently required for medical diagnosis. Miniature pressure sensors could directly measure the blood pressure and fluctuation in blood vessels with an inner diameter from 200 to 1000 μm. Glaucoma is a group of eye diseases usually resulting from abnormal intraocular pressure. The implantable pressure sensor for real-time inspection would keep the disease from worsening; meanwhile, these small devices could alleviate the discomfort of patients. In addition to medical applications, miniature pressure sensors have also been used in the aerospace, industrial, and consumer electronics fields. To clearly illustrate the “miniature size”, this paper focuses on miniature pressure sensors with an overall size of less than 2 mm × 2 mm or a pressure sensitive diaphragm area of less than 1 mm × 1 mm. In this paper, firstly, the working principles of several types of pressure sensors are briefly introduced. Secondly, the miniaturization with the development of the semiconductor processing technology is discussed. Thirdly, the sizes, performances, manufacturing processes, structures, and materials of small pressure sensors used in the different fields are explained in detail, especially in the medical field. Fourthly, problems encountered in the miniaturization of miniature pressure sensors are analyzed and possible solutions proposed. Finally, the probable development directions of miniature pressure sensors in the future are discussed.

Review of Laboratory Scale Models of Karst Aquifers: Approaches, Similitude, and Requirements

“…Digital measurement of pressure head by transducers and tracer concentrations by chemical sensors or digital imaging may enhance spatial and temporal densities of available data for mapping heterogeneities and simulating LSM responses to different stresses. Although digital pressure transducers have been used extensively in the past to obtain measurements at a point, there are new techniques to measure pressure including high‐pressure cell to measure chemo‐thermo‐mechanical characteristics of geomaterials (Abdul et al 2020), novel orifice to measure wide range of discharge and pressure in pressurized pipe network (Rezazadeh et al 2019), micro/nanopressure sensors for health monitoring and smart wearable devices (Chang et al 2020; Song et al 2020), and flexible sensors on surfaces (Fonov et al 2005; Chang et al 2020).…”

Impedance Spectroscopy of Lead-Free Ferroelectric Coatings

“…Two basic kinds of devices are preferred and commercially available in piezotronics in terms of constructive design and materials selection: solid substrate based (mainly semiconductors like silicon, or piezoelectric crystals like quartz), which are suitable for sensors applications [1][2][3], and flexible substrate based, suitable mainly for mechanical to electrical energy conversion (energy harvesting) [4,5]. Very often the way of characterization of such devices is conducted at a microstructural level considering the crystallinity, crystallographic planes, chemical composition and surface morphology of the piezoelectric films relating them further with the (piezoelectric voltage) = f (mass load) dependence.…”

Design and simulation of a novel dual current mirror based CMOS‐MEMS integrated pressure sensor

“…Monolithic integrated pressure sensors developed using microelectro-mechanical system (MEMS) and complementary-metaloxide semiconductor (CMOS) co-fabrication technologies on a single silicon chip are widely being used for biomedical and healthcare applications [1][2][3]. Among various physiological parameters, blood pressure (BP) plays an important role to indicate the health and well being of an individual [4].…”