scholarly journals Dynamic force measurements on swimming Chlamydomonas cells using micropipette force sensors

2020 ◽  
Vol 17 (162) ◽  
pp. 20190580
Author(s):  
Thomas J. Böddeker ◽  
Stefan Karpitschka ◽  
Christian T. Kreis ◽  
Quentin Magdelaine ◽  
Oliver Bäumchen
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Force Sensor ◽  
Bulk Liquid ◽  
Force Sensors ◽  
Dynamic Force ◽  
Force Measurements ◽  
Liquid Environment ◽  
Dynamic Forces ◽  
Force Calibration

Flagella and cilia are cellular appendages that inherit essential functions of microbial life including sensing and navigating the environment. In order to propel a swimming microorganism they displace the surrounding fluid by means of periodic motions, while precisely timed modulations of their beating patterns enable the cell to steer towards or away from specific locations. Characterizing the dynamic forces, however, is challenging and typically relies on indirect experimental approaches. Here, we present direct in vivo measurements of the dynamic forces of motile Chlamydomonas reinhardtii cells in controlled environments. The experiments are based on partially aspirating a living microorganism at the tip of a micropipette force sensor and optically recording the micropipette’s position fluctuations with high temporal and sub-pixel spatial resolution. Spectral signal analysis allows for isolating the cell-generated dynamic forces caused by the periodic motion of the flagella from background noise. We provide an analytic, elasto-hydrodynamic model for the micropipette force sensor and describe how to obtain the micropipette’s full frequency response function from a dynamic force calibration. Using this approach, we measure the amplitude of the oscillatory forces during the swimming activity of individual Chlamydomonas reinhardtii cells of 26 ± 5 pN, resulting from the coordinated flagellar beating with a frequency of 49 ± 5 Hz. This dynamic micropipette force sensor technique generalizes the applicability of micropipettes as force sensors from static to dynamic force measurements, yielding a force sensitivity in the piconewton range. In addition to measurements in bulk liquid environment, we study the dynamic forces of the biflagellated microswimmer in the vicinity of a solid/liquid interface. As we gradually decrease the distance of the swimming microbe to the interface, we measure a significantly enhanced force transduction at distances larger than the maximum extent of the beating flagella, highlighting the importance of hydrodynamic interactions for scenarios in which flagellated microorganisms encounter surfaces.

New Giant Magnetostrictive Force Sensors

2013 ◽  
Vol 816-817 ◽  
pp. 424-428
Author(s):  
Rong Ge Yan ◽  
Li Hua Zhu ◽  
Qing Xin Yang
Keyword(s):  
Force Measurement ◽  
Force Sensor ◽  
Measurement Range ◽  
Magnetic Flux Density ◽  
Force Sensors ◽  
Dynamic Force ◽  
Element Analysis ◽  
Giant Magnetostrictive Materials ◽  
Overload Capacity ◽  
Adjustable Range

Force sensors, based on the giant inverse magnetostrictive effect, have a series of outstanding properties, such as large overload capacity, which make them have more and more applications to the field of automatic control system of heavy industry, chemical industry. This paper designs new giant magnetostrictive force sensors using the rare-earth iron giant magnetostrictive materials. With the designed giant magnetostrictive force sensor, the relations between magnetic flux density in the gap and applied static stress on the sensor, the inductive voltage in the coil and time (with the dynamic stress), are calculated by finite element analysis software. The related confirmatory experiments have been conducted. The experimental results indicate that the giant magnetostrictive force sensor is fit for static and dynamic force measurement. In order to enlarge the measurement range, the designed force sensor as the basic cell is combined. This paper gives two kinds of combinations, which have the feature of adjustable range.

scholarly journals Generation of static and dynamic small calibration forces and their measurements by electromagnetic force compensation balance

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 113
Author(s):  
S. Vasilyan ◽  
N. Rogge ◽  
E. Manske ◽  
T. Fröhlich
Keyword(s):  
Electromagnetic Force ◽  
Force Sensor ◽  
Dynamic Force ◽  
Force Measurements ◽  
Photon Momentum ◽  
Differential Measurement ◽  
Measurement Mode ◽  
Reflection Configuration ◽  
Operational Modes ◽  
Force Compensation

The paper presents some of the results of the static and dynamic force measurements at 100 nN to sub-10 µN ranges which are generated due the photon-momentum. The force sensor with resolution about 20 nN and operating in differential measurement mode is developed by two electromagnetic force compensation balances. In order to generate these calibration forces, CW lasers with different operational modes, power levels, and wavelengths are used. Multi-reflection configuration of the laser beam inside the macroscopic cavity with highly reflective mirrors are used to test and variate the total amount of the forces.

Expanding the Horizons of Wireless Sensing

2022 ◽  
Vol 25 (3) ◽  
pp. 38-42
Author(s):  
Agrim Gupta ◽  
Cédric Girerd ◽  
Manideep Dunna ◽  
Qiming Zhang ◽  
Raghav Subbaraman ◽  
...  
Keyword(s):  
Force Sensor ◽  
Physical World ◽  
Contact Forces ◽  
Force Sensors ◽  
Force Measurements ◽  
Tissue Phantom ◽  
Ubiquitous Sensing ◽  
Sensing Applications ◽  
Communication Paradigm ◽  
Critical Requirement

All interactions of objects, humans, and machines with the physical world are via contact forces. For instance, objects placed on a table exert their gravitational forces, and the contact interactions via our hands/feet are guided by the sense of contact force felt by our skin. Thus, the ability to sense the contact forces can allow us to measure all these ubiquitous interactions, enabling a myriad of applications. Furthermore, force sensors are a critical requirement for safer surgeries, which require measuring complex contact forces experienced as a surgical instrument interacts with the surrounding tissues during the surgical procedure. However, with currently available discrete point-force sensors, which require a battery to sense the forces and communicate the readings wirelessly, these ubiquitous sensing and surgical sensing applications are not practical. This motivates the development of new force sensors that can sense, and communicate wirelessly without consuming significant power to enable a battery-free design. In this magazine article, we present WiForce, a low-power wireless force sensor utilizing a joint sensing-communication paradigm. That is, instead of having separate sensing and communication blocks, WiForce directly transduces the force measurements onto variations in wireless signals reflecting WiForce from the sensor. This novel trans-duction mechanism also allows WiForce to generalize easily to a length continuum, where we can detect as well as localize forces acting on the continuum. We fabricate and test our sensor prototype in different scenarios, including testing beneath a tissue phantom, and obtain sub-N sensing and sub-mm localizing accuracies (0.34 N and 0.6 mm, respectively).

scholarly journals Impact of thermal frequency drift on highest precision force microscopy using quartz-based force sensors at low temperatures

2014 ◽  
Vol 5 ◽  
pp. 407-412 ◽  
Author(s):  
Florian Pielmeier ◽  
Daniel Meuer ◽  
Daniel Schmid ◽  
Christoph Strunk ◽  
Franz J Giessibl
Keyword(s):  
Low Temperatures ◽  
Force Sensor ◽  
Frequency Variation ◽  
Force Sensors ◽  
Force Measurements ◽  
Temperature Changes ◽  
Force Microscopy ◽  
Atomic Force ◽  
New Type ◽  
The Stability

In frequency modulation atomic force microscopy (FM-AFM) the stability of the eigenfrequency of the force sensor is of key importance for highest precision force measurements. Here, we study the influence of temperature changes on the resonance frequency of force sensors made of quartz, in a temperature range from 4.8–48 K. The sensors are based on the qPlus and length extensional principle. The frequency variation with temperature T for all sensors is negative up to 30 K and on the order of 1 ppm/K, up to 13 K, where a distinct kink appears, it is linear. Furthermore, we characterize a new type of miniaturized qPlus sensor and confirm the theoretically predicted reduction in detector noise.

Experimental Investigation of Ribbed Cylinder's Vibroacoustics Transmissibility

2012 ◽  
Vol 516-517 ◽  
pp. 714-717
Author(s):  
Zhi Yong Xie ◽  
Qi Dou Zhou ◽  
Deng Yuan Mo
Keyword(s):  
Frequency Response ◽  
Sound Radiation ◽  
Force Sensor ◽  
Dynamic Force ◽  
Response Functions ◽  
Frequency Response Functions ◽  
Radiated Noise ◽  
Vibration And Sound Radiation ◽  
Force Calibration ◽  
Good Agreement

Exciting force's accurate measurement is crucial to the structure-born sound radiation. And the force sensor is calibrated by the dynamic force calibration equipment. Exciting force is accurately measured on the ribbed cylinder’s forced vibration and sound radiation. Based on the steady sine and random white noise exciting, the frequency response functions of the acceleration and sound pressure are obtained. Results obtained from the two methods are shown to be in good agreement with each other. According to the acceleration’s frequency response functions and sound pressure’s frequency response functions, it is obvious that the peak frequencies in the two frequency response functions are corresponding to each other. And the correspondence relationship could be used to help control the radiated noise.

Laryngeal Force Sensor: Quantifying Extralaryngeal Complications after Suspension Microlaryngoscopy

2018 ◽  
Vol 159 (2) ◽  
pp. 328-334 ◽  
Author(s):  
Allen L. Feng ◽  
Phillip C. Song
Keyword(s):  
Odds Ratio ◽  
Assessment Tool ◽  
Care Center ◽  
Tertiary Care ◽  
Force Sensor ◽  
Maximum Force ◽  
Dynamic Force ◽  
Force Measurements ◽  
The Mean ◽  
The Relationship

Objectives To develop a novel sensor capable of dynamically analyzing the force exerted during suspension microlaryngoscopy and to examine the relationship between force and postoperative tongue complications. Study Design Prospective observational study. Setting Academic tertiary care center. Methods The laryngeal force sensor is a designed for use during microphonosurgery. Prospectively enrolled patients completed pre- and postoperative surveys to assess the development of tongue-related symptoms (dysgeusia, pain, paresthesia, and paresis) or dysphagia (10-item Eating Assessment Tool [EAT-10]). To prevent operator bias, surgeons were blinded to the force recordings during surgery. Results Fifty-six patients completed the study. Of these, 20 (36%) developed postoperative tongue symptoms, and 12 (21%) had abnormal EAT-10 scores. The mean maximum force across all procedures was 164.7 N (95% CI, 141.0-188.4; range, 48.5-402.6), while the mean suspension time was 34.3 minutes (95% CI, 27.4-41.2; range, 7.1-108.1). Multiple logistic regression showed maximum force (odds ratio, 1.15; 95% CI, 1.02-1.29; P = .019) and female sex (30.1%; 95% CI, 22.7%-37.5%; P < .001) as significant predictors for the development of tongue-related symptoms. The only significant predictor of an abnormal postoperative EAT-10 score was an increased maximum force (odds ratio, 1.03; 95% CI, 1.00-1.06; P = .045). Conclusions The laryngeal force sensor is capable of providing dynamic force measurements throughout suspension microlaryngoscopy. An increase in maximum force during surgery may be a significant predictor for the development of tongue-related symptoms and an abnormal EAT-10 score. Female patients may also be at greater risk for developing postoperative tongue symptoms.

scholarly journals Displacements of the pipe system caused by a transient phenomenon using the dynamic forces measured in the laboratory

2018 ◽  
Vol 51 (9-10) ◽  
pp. 443-452 ◽  
Author(s):  
Agnieszka Malesińska ◽  
Mariusz Rogulski ◽  
Pierfabrizio Puntorieri ◽  
Giuseppe Barbaro ◽  
Beata Kowalska
Keyword(s):  
Transient Flow ◽  
System Size ◽  
Dynamic Force ◽  
Force Measurements ◽  
Flow Conditions ◽  
Motion Equations ◽  
Pipe System ◽  
Measurement Results ◽  
Dynamic Forces ◽  
The Impact

Background: When transporting liquids, in particularly over long distances, dynamic forces in the system can present a risk. The larger the system size, and the greater the pressure, the more harmful the impact is of such forces. Water is transported in this way for domestic, industrial, and fire-fighting purposes. One of the impulses of dynamic force application may be the transition of the pressure wave in the water hammer. Methods: In this paper, the results of measured dynamic forces and associated displacements recorded on the model caused by transient flow conditions are presented. For measured forces, the displacements of the pipe were also calculated by using the oscillation motion equations. Force measurements and displacement analyses were carried out in laboratory on the model of a simple fire protection system equipped with three nozzles. Results and Conclusions: The measurement results and calculations were used to calibrate a mathematical model created using MATLAB software.

Dynamic Compensation of Spindle Integrated Force Sensors With Kalman Filter

2004 ◽  
Vol 126 (3) ◽  
pp. 443-452 ◽  
Author(s):  
Simon S. Park ◽  
Yusuf Altintas
Keyword(s):  
Kalman Filter ◽  
Cutting Forces ◽  
Force Sensor ◽  
Force Sensors ◽  
Electric Force ◽  
Frequency Bandwidth ◽  
Force Measurements ◽  
Structural Dynamic ◽  
Signal Processing Method ◽  
Structural Dynamic Model

This paper presents a dynamically compensated Spindle Integrated Force Sensor (SIFS) system to measure cutting forces. Piezo-electric force sensors are integrated into the stationary spindle housing. The structural dynamic model between the cutting forces acting on the tool tip and the measured forces at the spindle housing is identified. The system is first calibrated to compensate the influence of spindle run-out and unbalance at different speeds. Using the cutting force signals measured at the spindle housing, a Kalman Filter is designed to filter the influence of structural modes on the force measurements. The frequency bandwidth of the proposed sensor system is significantly increased with the proposed sensing and the signal processing method.

Scanning Tunneling Microscopy and Atomic Force Microscopy of Enzymes and Enzyme Complexes

1990 ◽  
Vol 48 (3) ◽  
pp. 174-175
Author(s):  
Ronald D. Edstrom ◽  
Xiuru Yang ◽  
Mary E. Gurnack ◽  
Marcia A. Miller ◽  
Rui Yang ◽  
...  
Keyword(s):  
Cell Biology ◽  
Inorganic Ions ◽  
Bulk Liquid ◽  
Soluble Form ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Metabolic Channeling ◽  
Simplistic Notion ◽  
Soluble Enzymes

Many of the questions in biochemistry and cell biology are concerned with the relationships of proteins and other macromolecules in complex arrays which are responsible for carrying out metabolic sequences. The simplistic notion that the enzymes we isolate in soluble form from the cytoplasm were also soluble in vivo is being replaced by the concept that these enzymes occur in organized systems within the cell. In this newer view, the cytoplasm is organized and the “soluble enzymes” are in fact fixed in the cellular space and the only soluble components of the cell are small metabolites, inorganic ions etc. Further support for the concept of metabolic organization is provided by the evidence of metabolic channeling. It has been shown that for some metabolic pathways, the intermediates are not in free diffusion equilibrium with the bulk liquid in the cell but are passed along, more or less directly, from one enzyme to the next.

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