scholarly journals Test-Bench for the Characterization of Flexion Sensors Used in Biomechanics

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2994
Author(s):  
Monica Tiboni ◽  
Azzurra Filippini ◽  
Cinzia Amici ◽  
David Vetturi
Keyword(s):  
Statistical Analysis ◽  
Test Bench ◽  
Low Cost ◽  
Wearable Devices ◽  
Radius Of Curvature ◽  
Structural Components ◽  
Good Repeatability ◽  
Fixed Radius ◽  
Biomedical Field

The design, prototyping and validation of an innovative test bench for the characterization and the hysteresis measurement of flexion sensors are presented in this paper. The device, especially designed to test sensors employed in the biomedical field, can be effectively used to characterize also sensors intended for other applications, such as wearable devices. Flexion sensors are widely adopted in devices for biomedical purposes and in this context are commonly used in two main ways: to measure movements (i) with fixed radius of curvature and (ii) with variable radius of curvature. The test bench has been conceived and designed with reference to both of these needs of use. The technological choices have been oriented towards simplicity of manufacture and assembly, configuration flexibility and low cost of realization. For this purpose, 3D printing technology was chosen for most of the structural components of the device. To verify the test bench performances, a test campaign was carried out on five commercial bending sensors. To characterize each sensor, the acquired measurements were analysed by assessing repeatability and linearity of the sensors and hysteresis of the system sensor/test bench. A statistical analysis was performed to study the positioning repeatability and the hysteresis of the device. The results demonstrate good repeatability and low hysteresis.

scholarly journals Quality Assessment of Single-Channel EEG for Wearable Devices

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 601 ◽  
Author(s):  
Fanny Grosselin ◽  
Xavier Navarro-Sune ◽  
Alessia Vozzi ◽  
Katerina Pandremmenou ◽  
Fabrizio De Vico Fallani ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Single Channel ◽  
Low Cost ◽  
Wearable Devices ◽  
Brain State ◽  
Eeg Signals ◽  
Many Sources ◽  
The Brain

The recent embedding of electroencephalographic (EEG) electrodes in wearable devices raises the problem of the quality of the data recorded in such uncontrolled environments. These recordings are often obtained with dry single-channel EEG devices, and may be contaminated by many sources of noise which can compromise the detection and characterization of the brain state studied. In this paper, we propose a classification-based approach to effectively quantify artefact contamination in EEG segments, and discriminate muscular artefacts. The performance of our method were assessed on different databases containing either artificially contaminated or real artefacts recorded with different type of sensors, including wet and dry EEG electrodes. Furthermore, the quality of unlabelled databases was evaluated. For all the studied databases, the proposed method is able to rapidly assess the quality of the EEG signals with an accuracy higher than 90%. The obtained performance suggests that our approach provide an efficient, fast and automated quality assessment of EEG signals from low-cost wearable devices typically composed of a dry single EEG channel.

Test Bench for Characterization and Durability Tests of Motorbike Clutches

2021 ◽  
Author(s):  
G. Previati ◽  
M. Gobbi
Keyword(s):  
Test Bench ◽  
Friction Material ◽  
Operating Conditions ◽  
Test Rig ◽  
Automatic Transmissions ◽  
Different Temperatures ◽  
Durability Assessment ◽  
Good Repeatability ◽  
The One

Abstract In the paper, a new test bench for characterization and durability assessment of multi disc wet clutches for motorbike applications is presented. The design of the new test bench is inspired by the current SAE standards J2490 and J286 that refer to the testing of friction material for automatic transmissions wet clutches. Differently from the test bench described in the two standards, which is mainly designed to test the friction material, the test bench presented in this paper has been designed for testing the whole clutch, comprising all discs and the actuation mechanism. The lubrication system of the clutch utilized on the test bench is very similar to the one present on the actual motorbike. The design and instrumentation of the new test rig is analysed and discussed in the paper. The test bench has been used for the characterization of different motorbike clutches. The bench has proved to be able to measure the clutch characteristic for different temperatures and clutch wear levels. A very good repeatability of the tests has been achieved allowing for a comparison of different clutches design, friction material properties and operating conditions (temperature, ..). Some experimental results are presented and discussed in the paper.

scholarly journals Development and Characterization of a Low-Cost Sensors System for an Acoustic Test Bench

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6663
Author(s):  
Ciro Moreno-Ramírez ◽  
Carmen Iniesta ◽  
Alejandro González ◽  
José Luis Olazagoitia
Keyword(s):  
Test Bench ◽  
Mechanical Design ◽  
Dynamic Pressure ◽  
Low Cost ◽  
Pressure Sensors ◽  
Acquisition System ◽  
Sampling System ◽  
Thermoacoustic Engines ◽  
And Control

Existing acoustic test benches are usually costly devices based on proprietary designs, sensors, and acquisition devices. In this paper, a low-cost test bench for acoustic purposes is introduced. The design of the test bench takes into account not only the low-cost mechanical design, but also uses low-cost sensors and control boards. This test bench has been designed for a range of signals compatible with those used by thermoacoustic engines, but it can be useful for applications with similar requirements. Taking advantage of an auxiliary pressure reference, low-cost unidirectional differential pressure sensors can be used to significantly increase the accuracy of the sampling system. The acoustic and mechanical design and development are presented along with the sampling system and the sensors arrangement implemented. Both the sensor and sampling system are evaluated by comparison with a high-fidelity sound acquisition system. An unexpected effect on the time error values distribution of the low-cost acquisition system is found and described. Finally, the errors introduced by the system and the sensors in terms of time and pressure sampling are characterized. As a result, the low-cost system’s accuracy has been satisfactory assessed and validated for the conditions expected in thermoacoustic experiments in terms of frequency and dynamic pressure.

scholarly journals Thermal Characterization of New 3D-Printed Bendable, Coplanar Capacitive Sensors

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6324
Author(s):  
Mattia Alessandro Ragolia ◽  
Anna M. L. Lanzolla ◽  
Gianluca Percoco ◽  
Gianni Stano ◽  
Attilio Di Nisio
Keyword(s):  
Sunflower Oil ◽  
Low Cost ◽  
Thermoplastic Polyurethane ◽  
Thermal Characterization ◽  
Capacitive Sensor ◽  
Fused Filament Fabrication ◽  
Level Measurement ◽  
3D Printed ◽  
Good Repeatability

In this paper a new low-cost stretchable coplanar capacitive sensor for liquid level sensing is presented. It has been 3D-printed by employing commercial thermoplastic polyurethane (TPU) and conductive materials and using a fused filament fabrication (FFF) process for monolithic fabrication. The sensor presents high linearity and good repeatability when measuring sunflower oil level. Experiments were performed to analyse the behaviour of the developed sensor when applying bending stimuli, in order to verify its flexibility, and a thermal characterization was performed in the temperature range from 10 °C to 40 °C to evaluate its effect on sunflower oil level measurement. The experimental results showed negligible sensitivity of the sensor to bending stimuli, whereas the thermal characterization produced a model describing the relationship between capacitance, temperature, and oil level, allowing temperature compensation in oil level measurement. The different temperature cycles allowed to quantify the main sources of uncertainty, and their effect on level measurement was evaluated.

scholarly journals Microstructure and Thermoelectric Properties of (Bi0.48Sb1.52)Te3 Thick Films Prepared with Tape Casting Method

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 140
Author(s):  
Lichen Liu ◽  
Ziping Cao ◽  
Min Chen ◽  
Jun Jiang
Keyword(s):  
Thermoelectric Properties ◽  
Low Cost ◽  
Thick Films ◽  
Tape Casting ◽  
Casting Process ◽  
Casting Method ◽  
Glass Substrates ◽  
Conductive Films ◽  
Casting Technology

This paper reports the fabrication and characterization of (Bi0.48Sb1.52)Te3 thick films using a tape casting process on glass substrates. A slurry of thermoelectric (Bi0.48Sb1.52)Te3 was developed and cured thick films were annealed in a vacuum chamber at 500–600 °C. The microstructure of these films was analyzed, and the Seebeck coefficient and electric conductivity were tested. It was found that the subsequent annealing process must be carefully designed to achieve good thermoelectric properties of these samples. Conductive films were obtained after annealing and led to acceptable thermoelectric performance. While the properties of these initial materials are not at the level of bulk materials, this work demonstrates that the low-cost tape casting technology is promising for fabricating thermoelectric modules for energy conversion.

scholarly journals Biomedical application of photo-crosslinked gelatin hydrogels

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Lei Xiang ◽  
Wenguo Cui
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Biomedical Application ◽  
Biomedical Field ◽  
Or Gene ◽  
Tunable Mechanical Properties ◽  
Bio Compatibility ◽  
Regeneration Of Bone ◽  
Development Prospects

Abstract During the past decades, photo-crosslinked gelatin hydrogel (methacrylated gelatin, GelMA) has gained a lot of attention due to its remarkable application in the biomedical field. It has been widely used in cell transplantation, cell culture and drug delivery, based on its crosslinking to form hydrogels with tunable mechanical properties and excellent bio-compatibility when exposed to light irradiation to mimic the micro-environment of native extracellular matrix (ECM). Because of its unique biofunctionality and mechanical tenability, it has also been widely applied in the repair and regeneration of bone, heart, cornea, epidermal tissue, cartilage, vascular, peripheral nerve, oral mucosa, and skeletal muscle et al. The purpose of this review is to summarize the recent application of GelMA in drug delivery and tissue engineering field. Moreover, this review article will briefly introduce both the development of GelMA and the characterization of GelMA. Finally, we discuss the challenges and future development prospects of GelMA as a tissue engineering material and drug or gene delivery carrier, hoping to contribute to accelerating the development of GelMA in the biomedical field. Graphical abstract

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