scholarly journals Self-made 3D-printed encapsulation of thin-film transducers for reliable force measurement in biomedical applications

2021 ◽  
Author(s):  
Raffaele Pertusio ◽  
Silvestro Roatta

In biomedical studies as well as in clinical trials, it is often useful to have a reliable measure of the force exerted by the body(eg. clenching force at the teeth or pinch force at fingertips) or on the body by external stimuli (eg. taps to elicit reflexes orlocal pressure for nociceptive stimulation). Thin-film sensors such as FlexiForce ® provide a very handy and versatile solutionfor these application, but can be easily damaged and offer poor accuracy and repeatability, being heavily affected by thesurface material they get in contact with. The aim of the study is the realization of a 3D-printed cover that completely embedsthe sensor, thus providing mechanical protection and increasing reliability of the measurement. The increasing availability of3D printers and of printing materials for medical use allows the user to shape the cover according to specific needs, with shortdeveloping time and low cost.

2007 ◽  
Vol 1010 ◽  
Author(s):  
Janagama Goud ◽  
P. Markondeya Raj ◽  
Jin Liu ◽  
Mahadevan Iyer ◽  
Z. L. Wang ◽  
...  

AbstractSemiconducting oxides are widely known and commercially applied for their gas sensing properties. However, biochemical sensing has mostly depended on optical and electrochemical techniques that are more cumbersome. This work investigates the biosensing characteristics of ZnO nanobelts and ZnO thin films. Zinc oxide thin film sensors showed changes in conductivity after protein functionalization with rabbit IgG and hybridization with anti-rabbit IgG. Conductivity changes were also measured after coating the oxides with MCF-7 cancer cells and its antibodies. In another set of experiments, ZnO nanobelts showed systematic conductivity changes with rabbit IgG protein hybridization. The experimental results in this paper indicate that the conductimetric properties of nano and thin film oxides can be sensitized to protein and cancer cell hybridization reactions. This technique can also be applied to certain other pathogen proteins or toxic proteins from the environment leading to low-cost miniaturized wireless biosensors.


2013 ◽  
Vol 569-570 ◽  
pp. 515-522 ◽  
Author(s):  
Lars P. Mortensen ◽  
Dong Hyeon Ryu ◽  
Ying Jun Zhao ◽  
Kenneth J. Loh

Wind is a competitive, clean, and fast-growing renewable energy industry. However, in order for wind to compete with fossil fuel-based energies, it is necessary to achieve lower cost of energy. One way is to reduce operations and maintenance costs by integrating structural health monitoring (SHM) systems with wind turbines. It has been found that the fiber-reinforced polymer (FRP) composite-based wind blades are susceptible to damage (e.g., cracks, debonding, and impact). Damage is typically invisible to the naked eye and can propagate rapidly to cause sudden failure. This work presents a new SHM approach using embedded thin film sensors for detecting damage in FRP-based wind blades. While previous studies have shown that carbon nanotube-based thin films can be incorporated with FRPs for sensing, this study further investigates their electromechanical properties. First, a unique spray fabrication approach was employed so that films can be assembled on a low cost basis and can be deposited onto any substrate or structure. Second, the electrical properties of films subjected to post-fabrication thermal annealing were compared. Finally, freestanding films were prepared and subjected to uniaxial tensile cyclic loading while their resistivity was measured simultaneously. The results showed that these films were piezoresistive.


Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4031 ◽  
Author(s):  
Ming Luo ◽  
Zenghui Chong ◽  
Dongsheng Liu

In the milling process, cutting forces contain key information about the machining process status in terms of workpiece quality and tool condition. On-line cutting force measurement is key for machining condition monitoring and machined surface quality assurance. This paper presents a novel instrumented working table with integrated polyvinylidene fluoride (PVDF) thin-film sensors, thus enabling the dynamic milling force measurement with compact structures. To achieve this, PVDF thin-film sensors are integrated into the working table to sense forces in different directions and the dedicated cutting force decoupling model is derived. A prototype instrumented working table is developed and validated. The validation demonstrates that profiles of the forces measured from the developed instrumented working table prototype and the dynamometer match well. Furthermore, the milling experiment results convey that the instrumented working table prototype could also identify the tool runout due to tool manufacturing or assembly errors, and the force signal spectrum analysis indicates that the developed working table can capture the tool passing frequency correctly, therefore, is suitable for the milling force measurement.


Author(s):  
P.A. Trunin ◽  
A.M. Meleshnikov ◽  
M.A. Solovyev ◽  
A.A. Vorotnikov

The presence of force-moment sensing of robotic systems makes it possible to improve the quality of the interaction between the robot and the objects of the external environment. There are many ways to provide force-moment sensing, one of which is to use multicomponent force sensors. However, their cost is quite high, so it is important to search and develop more profitable technical solutions. In this regard, a three-component force measurement sensor was developed, built on the basis of an elastic silicone element, with a built-in permanent magnet, and a hall-effect magnetometer. This technical solution is low-cost. The paper describes the technological process for the production of a three-component force measurement sensor, based on 3D printing of the body with an FDM printer, which makes it cheap to manufacture, and molding of two-component silicone. The paper considers the process of soldering SMD components to boards using a soldering hair dryer, stencils and solder paste, and shows a stand for calibrating the manufactured sensors, consisting of micrometric screws and parts printed on an FDM 3D printer. The mathematical method for calibration is based on the least squares method. The result of calibration of a three-component force measurement sensor is given. The research results in the development of a working sensor with the following characteristics: resolution — 1 mN, sensor sensitivity — 0.005 T / N.


2019 ◽  
Author(s):  
Noha Hamada Mohamed ◽  
Hossam Kandil ◽  
Iman Ismail Dakhli

Abstract In dentistry, 3D printing already has diverse applicability, and holds a great deal of promise to make possible many new and exciting treatments and approaches to manufacturing dental restorations. Better availability, shorter processing time, and descending costs have resulted in the increased use of RP. Concomitantly the development of medical applications is expanding. (Zaharia et al., 2017)Many different printing technologies exist, each with their own advantages and disadvantages. Unfortunately, a common feature of the more functional and productive equipment is the high cost of the equipment, the materials, maintenance, and repair, often accompanied by a need for messy cleaning, difficult post-processing, and sometimes onerous health and safety concerns (Dawood et al., 2015)Low-cost 3D printers represent a great opportunity in the dental and medical field, as they could allow surgeons to use 3D models at a very low cost and, therefore, democratize the use of these 3D models in various indications. However, efforts should be made to establish a unified validation protocol for low-cost RP 3D printed models, including accuracy, reproducibility, and repeatability tests. Asaumi et al., suggested that dimensional changes may not affect the success of surgical applications if such changes are within a 2% variation .However, the proposed cut-off of 2% should be furthermore discussed, as the same accuracy may be not required for all types of indications. (Silva et al., 2008; Maschio et al., 2016)This aim of the present study is to evaluate the dimensional accuracy of the 3D printed mandibular models fabricated by two different additive manufacturing techniques, using highly precise one as selective laser sintering (SLS) and a low-cost one as fused filament fabrication and whether they are both comparable in terms of precision. In addition to evaluation of dimensional accuracy of linear measurements of the mandible in CBCT scans.7 mandibular models will be recruited. Radio-opaque markers of gutta-percha balls will be applied on the model to act as guide pointsTen linear measurements (5 long distances: Inter-condylar, inter-coronoidal, inter-mandibular notch, length of left ramus, length of right ramus; as well as 5 short distances: Length of the body of the mandible at midline, length of the body of the mandible in the area of last left molar, as well as that of the last right molar, the distance between the tip of right condyle to the tip of the right coronoid, as well as that of their left counterparts) will be obtained using digital calliper, to act as the reference standard later. Scanning of the model by CBCT will be next , 3D printing of the scanned image using SLS and FFF printers will be done. Recording of same linear measurment will be done on printed models. Comparison of the recorded values vs reference standard is the last step


2021 ◽  
Vol 63 (9) ◽  
pp. 1290
Author(s):  
Г.В. Курляндская ◽  
А.П. Сафронов ◽  
С.В. Щербинин ◽  
И.В. Бекетов ◽  
Ф.А. Бляхман ◽  
...  

This work describes the possibility of fabrication of the large batches of magnetic nanoparticles using electrophysical methods of electric explosion of the wire, laser target evaporation and spark discharge. Bioapplications of nanoparticles require the production of magnetic materials in the form of stabilized aqueous suspensions or hydrogels with magnetic fillers; therefore, some details of the synthesis of these materials and their certification are discussed. The peculiarities of interaction of magnetic nanoparticles with biological systems, the problem of biocompatibility, the possibility of using ferrogel substrates for the needs of cell technologies and regenerative medicine, as well as implication of biomimetics in the development of magnetic biosensors are considered. The results of the analysis of a number of different biological experiments carried out with suspensions of various types, obtained based on the same batch of MNPs are presented. An analysis of examples of magnetic biodetection and existing theoretical approaches will make it possible to assess the prospects of this scientific direction for the creation of highly sensitive thin film sensors based on the giant magnetoimpedance effect for biomedical applications


2019 ◽  
Vol 798 ◽  
pp. 65-70
Author(s):  
Jintamai Suwanprateeb

Synthetic polymers are widely used in biomedical applications due to their advantages compared to other materials including low cost and ease of processability, good corrosion resistance and high properties to weight ratio. Among several polymeric biomaterials, polyethylene is a biocompatible polymer which has a long history of being utilized in many biomedical applications ranging from simple components to advanced implants. Although dense polyethylene is known to be a bioinert material which does not interact with host tissue, polyethylene in its appropriate porous form has been shown to be able to integrate well with surrounding host tissues and could widen its uses as bioactive implants. Porous polyethylene structure which was fabricated by three dimensional printing (3DP) is demonstrated. Its manufacturing technique, properties and clinical applications as tissue integrated implants which permitted soft or hard tissue ingrowth in tissue regeneration and replacement is discussed.


RSC Advances ◽  
2018 ◽  
Vol 8 (32) ◽  
pp. 18074-18083 ◽  
Author(s):  
Apsar Pasha ◽  
Syed Khasim ◽  
Omar A. Al-Hartomy ◽  
Mohana Lakshmi ◽  
K. G. Manjunatha

In this study, for the first time we report the fabrication of low-cost ethylene glycol (EG)-doped PEDOT–PSS (poly 3,4-ethylenedioxythiophene:polystyrene sulfonate) organic thin film sensors for the detection of LPG at room temperature.


Author(s):  
T. P. Nolan

Thin film magnetic media are being used as low cost, high density forms of information storage. The development of this technology requires the study, at the sub-micron level, of morphological, crystallographic, and magnetic properties, throughout the depth of the deposited films. As the microstructure becomes increasingly fine, widi grain sizes approaching 100Å, the unique characterization capabilities of transmission electron microscopy (TEM) have become indispensable to the analysis of such thin film magnetic media.Films were deposited at 225°C, on two NiP plated Al substrates, one polished, and one circumferentially textured with a mean roughness of 55Å. Three layers, a 750Å chromium underlayer, a 600Å layer of magnetic alloy of composition Co84Cr14Ta2, and a 300Å amorphous carbon overcoat were then sputter deposited using a dc magnetron system at a power of 1kW, in a chamber evacuated below 10-6 torr and filled to 12μm Ar pressure. The textured medium is presently used in industry owing to its high coercivity, Hc, and relatively low noise. One important feature is that the coercivity in the circumferential read/write direction is significandy higher than that in the radial direction.


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