Piezoresistive sensors are among the earliest micromachined silicon devices. The need for smaller, less expensive, higher performance sensors helped drive early micromachining technology, a precursor to microsystems or microelectromechanical systems (MEMS). The effect of stress on doped silicon and germanium has been known since the work of Smith at Bell Laboratories in 1954. Since then, researchers have extensively reported on microscale, piezoresistive strain gauges, pressure sensors, accelerometers, and cantilever force/displacement sensors, including many commercially successful devices. In this paper, we review the history of piezoresistance, its physics and related fabrication techniques. We also discuss electrical noise in piezoresistors, device examples and design considerations, and alternative materials. This paper provides a comprehensive overview of integrated piezoresistor technology with an introduction to the physics of piezoresistivity, process and material selection and design guidance useful to researchers and device engineers.

/pdf/review-semiconductor-piezoresistance-for-microsystems-2i2jehwa4g.pdf

Review: Semiconductor Piezoresistance for Microsystems

The Myofibroblast: one function, multiple origins

The organizing principle: microenvironmental influences in the normal and malignant breast Mina J. Bissell 1,* , Derek C. Radisky 1 , Aylin Rizki 1 , Valerie M. Weaver 2 , Ole W. Petersen 3 Life Sciences Division, Lawrence Berkeley National Laboratory One Cyclotron Road, MS 977R225A, Berkeley, CA 94720, USA Department of Pathology and Institute for Medicine and Engineering University of Pennsylvania, PA, USA Structural Cell Biology Unit, Institute of Medical Anatomy The Panum Institute, Copenhagen, Denmark Corresponding Author: Mina J. Bissell Life Sciences Division, Lawrence Berkeley National Laboratory One Cyclotron Road, MS 977R225A, Berkeley, CA 94720, USA e-mail: mjbissell/lbl.gov Tel: +1 510 486 4365 Fax: +1 510 486 5586

The organizing principle: microenvironmental influences in the normal and malignant breast

Mechanotransduction - how cells sense physical forces and translate them into biochemical and biological responses - is a vibrant and rapidly-progressing field, and is important for a broad range of biological phenomena. This forum explores the role of mechanotransduction in a variety of cellular activities and highlights intriguing questions that deserve further attention.

/pdf/mechanotransduction-use-the-force-s-26m7l83j5x.pdf

Mechanotransduction: use the force(s)

An elastic strain sensor can be incorporated into an artificial skin that can sense flexing by the underlying support structure of the skin to detect and track motion of the support structure. The unidirectional elastic strain sensor can be formed by filling two or more channels in an elastic substrate material with a conductive liquid. At the ends of the channels, a loop port connects the channels to form a serpentine channel. The channels extend along the direction of strain and the loop portions have sufficiently large cross-sectional area in the direction transverse to the direction of strain that the sensor is unidirectional. The resistance is measured at the ends of the serpentine channel and can be used to determine the strain on the sensor. Additional channels can be added to increase the sensitivity of the sensor. The sensors can be stacked on top of each other to increase the sensitivity of the sensor. In other embodiments, two sensors oriented in different directions can be stacked on top of each other and bonded together to form a bidirectional sensor. A third sensor formed by in the shape of a spiral or concentric rings can be stacked on top and used to sense contact or pressure, forming a three dimensional sensor. The three dimensional sensor can be incorporated into an artificial skin to provide advanced sensing.

Artificial skin and elastic strain sensor

This paper presents the design, fabrication, and characterization of unique piezoresistive microfabricated shear stress sensors for direct measurements of shear stress underwater. Sidewall-implanted piezoresistors measure lateral force (integrated shear stress) and traditional top-implanted piezoresistors detect normal forces. In addition to the oblique-implant technique, the fabrication process includes a hydrogen anneal step to smooth scalloped silicon sidewalls left by the deep reactive ion etch (DRIE) process. This step was found to reduce the 1/ f noise level by almost an order of magnitude for the sidewall-implanted piezoresistors. Lateral sensitivity was characterized using a microfabricated silicon cantilever force sensor. Out-of-plane sensitivity was evaluated by laser Doppler vibrometry and resonance of the plate element. In-plane sensitivity and out-of-plane crosstalk were characterized, as well as hysteresis and repeatability of the measurements. TSUPREM-4 simulations were used to investigate the discrepancies between the theoretical and experimental values of sidewall-implanted piezoresistor sensitivity. The sensors are designed to be used underwater for studies of hydrodynamic flows.

Design and characterization of microfabricated piezoresistive floating element-based shear stress sensors

We present design and experimental implementation of electrostatic comb-drive actuators in solutions of high conductivity relevant for biological cells. The actuators are operated in the frequency range 1-10 MHz in ionic and biological cell culture media, with ionic strengths up to 150 mmol/L. Typical displacement is 3.5 mum at an applied peak-to-peak signal of 5 V. Two different actuation schemes are presented and tested for performance at high frequency. A differential drive design is demonstrated to overcome the attenuation due to losses in parasitic impedances. The frequency dependence of the electrostatic force has been characterized in media of different ionic strengths. Circuit models for the electric double layer phenomena are used to understand and predict the actuator behavior. The actuator is integrated into a planar force sensing system to measure the stiffness of cells cultured on suspended structures.

/pdf/mems-electrostatic-actuation-in-conducting-biological-media-4kpl8gc83z.pdf

MEMS Electrostatic Actuation in Conducting Biological Media

Mechanical forces are among important factors that drive cellular function and organization. We present a microfabricated device with on-chip actuation for mechanical testing of single cells. An integrated immersible electrostatic actuator system is demonstrated that applies calibrated forces to cells. We conduct stretching experiments by directly applying forces to epithelial cells adhered to device surfaces functionalized with collagen. We measure mechanical properties including stiffness, hysteresis and visco-elasticity of adherent cells.

/pdf/microactuator-device-for-integrated-measurement-of-21kz032122.pdf

Microactuator device for integrated measurement of epithelium mechanics.

We report on the design and performance of underwater piezoresistive floating-element shear stress sensors for direct dynamic measurements. Our design utilizes sidewall-implanted piezoresistors to measure lateral force and infer shear stress, and traditional top-implanted piezoresistors to detect normal forces and pressure transients. A gravity-driven flume was used to test the sensors. FEMLAB simulation and microscale Particle Image Velocimetry experiments were used to characterize the flow disturbance over different gap sizes. The results show no detectable disturbance of the flow over the range of sensor gap sizes evaluated (5-20 µ m).

Piezoresistive MEMS Underwater Shear Stress Sensors

/pdf/experimental-characterization-of-frequency-dependent-4hhq8fx46r.pdf

Experimental characterization of frequency dependent electrostatic actuator for aqueous media

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Vikram Mukundan

Author Tools

Chat about Author