A Preliminary Study on 3D Printed Smart Insoles With Stretchable Piezoresistive Sensors for Plantar Pressure Monitoring

2017 ◽  
Author(s):  
Md Omar Faruk Emon ◽  
Jae-Won Choi
Keyword(s):  
Screen Printing ◽  
Pressure Sensors ◽  
Heel Strike ◽  
Pressure Monitoring ◽  
Piezoresistive Sensors ◽  
Flexible Material ◽  
Entire Structure ◽  
Multi Walled Carbon Nanotube ◽  
3D Printed ◽  
Preliminary Study

In this report, we present a 3D printed insole which has multiple soft pressure sensors inserted in it to detect the force on the sole including heel, midfoot, and forefoot as well as timing and location of the strike while walking. The insole was 3D printed using a soft and flexible material having multiple open channels on it to attach sensors. Flexible and stretchable piezoresistive sensors were fabricated via screen printing and molding processes. The multi-layer sensor comprises an ionic liquid (IL) based piezoresistive layer sandwiched between two multi-walled carbon nanotube (MWCNT) based stretchable electrodes and finally, top and bottom insulation layers. The sensor was constructed using 3D printable photopolymer as 3D printing is our target manufacturing technique to build the entire structure including insole. The sensor embedded insole was evaluated for different foot landing conditions such as heel strike, midfoot strike, and forefoot strike. Experimental results showed that the developed insole could indicate the amount of force on insole when foot hits ground, with timing and location of the strike.

scholarly journals Integration of 3D Printed Flexible Pressure Sensors into Physical Interfaces for Wearable Robots

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2157
Author(s):  
Kevin Langlois ◽  
Ellen Roels ◽  
Gabriël Van De Velde ◽  
Cláudia Espadinha ◽  
Christopher Van Vlerken ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Human Subjects ◽  
Pressure Sensors ◽  
Poor Performance ◽  
Capacitive Pressure Sensor ◽  
Upper Arm ◽  
Seamless Integration ◽  
Dynamic Task ◽  
Wearable Robots ◽  
3D Printed

Sensing pressure at the physical interface between the robot and the human has important implications for wearable robots. On the one hand, monitoring pressure distribution can give valuable benefits on the aspects of comfortability and safety of such devices. Additionally, on the other hand, they can be used as a rich sensory input to high level interaction controllers. However, a problem is that the commercial availability of this technology is mostly limited to either low-cost solutions with poor performance or expensive options, limiting the possibilities for iterative designs. As an alternative, in this manuscript we present a three-dimensional (3D) printed flexible capacitive pressure sensor that allows seamless integration for wearable robotic applications. The sensors are manufactured using additive manufacturing techniques, which provides benefits in terms of versatility of design and implementation. In this study, a characterization of the 3D printed sensors in a test-bench is presented after which the sensors are integrated in an upper arm interface. A human-in-the-loop calibration of the sensors is then shown, allowing to estimate the external force and pressure distribution that is acting on the upper arm of seven human subjects while performing a dynamic task. The validation of the method is achieved by means of a collaborative robot for precise force interaction measurements. The results indicate that the proposed sensors are a potential solution for further implementation in human–robot interfaces.

scholarly journals Wearable Sensor-Based Real-Time Gait Detection: A Systematic Review

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2727
Author(s):  
Hari Prasanth ◽  
Miroslav Caban ◽  
Urs Keller ◽  
Grégoire Courtine ◽  
Auke Ijspeert ◽  
...  
Keyword(s):  
Systematic Review ◽  
Gait Analysis ◽  
Real Time ◽  
Wearable Sensors ◽  
Pressure Sensors ◽  
Clinical Applications ◽  
Performance Comparison ◽  
Heel Strike ◽  
Rule Based ◽  
Pathological Gait

Gait analysis has traditionally been carried out in a laboratory environment using expensive equipment, but, recently, reliable, affordable, and wearable sensors have enabled integration into clinical applications as well as use during activities of daily living. Real-time gait analysis is key to the development of gait rehabilitation techniques and assistive devices such as neuroprostheses. This article presents a systematic review of wearable sensors and techniques used in real-time gait analysis, and their application to pathological gait. From four major scientific databases, we identified 1262 articles of which 113 were analyzed in full-text. We found that heel strike and toe off are the most sought-after gait events. Inertial measurement units (IMU) are the most widely used wearable sensors and the shank and foot are the preferred placements. Insole pressure sensors are the most common sensors for ground-truth validation for IMU-based gait detection. Rule-based techniques relying on threshold or peak detection are the most widely used gait detection method. The heterogeneity of evaluation criteria prevented quantitative performance comparison of all methods. Although most studies predicted that the proposed methods would work on pathological gait, less than one third were validated on such data. Clinical applications of gait detection algorithms were considered, and we recommend a combination of IMU and rule-based methods as an optimal solution.

Preliminary Study of Alginates Extracted from Brown Algae (Sargassum sp.) Available in Madura Island as Composite Based Hydrogel Materials

2019 ◽  
Vol 964 ◽  
pp. 240-245 ◽  
Author(s):  
Amaliya Rasyida ◽  
Thalyta Rizkha Pradipta ◽  
Sigit Tri Wicaksono ◽  
Vania Mitha Pratiwi ◽  
Yeny Widya Rakhmawati
Keyword(s):  
Sodium Alginate ◽  
Brown Algae ◽  
Extraction Process ◽  
Composition Analysis ◽  
3D Printer ◽  
X Ray Diffraction ◽  
X Ray ◽  
3D Printed ◽  
Preliminary Study

Utilization of brown algae especially in Madura, where it’s close to Surabaya, only limited for food. This become a reference for developing and increasing the potential of this algae by extracting one of the ingredients, namely alginate. This paper deals with the characterization of sodium alginate extracted from sargassum sp. using modified-purified calcium routes. The extracted sodium alginate will be further used as composite hydrogel materials and compared with commercial sodium alginate. Hereafter, the synthesized composite is expected to be bio-ink for 3d printer. Chemical composition analysis were analyzed using X-Ray Fluorosense (XRF) followed by Fourier-transform infrared spectroscopy (FTIR) analysis to identify the functional group of composite and X-Ray Diffraction (XRD). Furthermore, viscosity bath is performed to compare the viscosity of extracted and commercial one. The result shows that modified-purified calcium routes in the extraction process of sodium alginate is desirable for improving their properties. Interestingly enough, with the goal of using it as bio-ink in 3d printed fabrication, the synthesized composite shows viscosity, 300 cSt, which meets the criteria for bio-ink in 3d printer.

scholarly journals Tunable In Situ 3D-Printed PVDF-TrFE Piezoelectric Arrays

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5032
Author(s):  
Alec Ikei ◽  
James Wissman ◽  
Kaushik Sampath ◽  
Gregory Yesner ◽  
Syed N. Qadri
Keyword(s):  
3D Printing ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Mechanical Strain ◽  
Pressure Sensors ◽  
Strain Ratio ◽  
Ex Situ ◽  
Order Of Magnitude ◽  
3D Printed

In the functional 3D-printing field, poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) has been shown to be a more promising choice of material over polyvinylidene fluoride (PVDF), due to its ability to be poled to a high level of piezoelectric performance without a large mechanical strain ratio. In this work, a novel presentation of in situ 3D printing and poling of PVDF-TrFE is shown with a d33 performance of up to 18 pC N−1, more than an order of magnitude larger than previously reported in situ poled polymer piezoelectrics. This finding paves the way forward for pressure sensors with much higher sensitivity and accuracy. In addition, the ability of in situ pole sensors to demonstrate different performance levels is shown in a fully 3D-printed five-element sensor array, accelerating and increasing the design space for complex sensing arrays. The in situ poled sample performance was compared to the performance of samples prepared through an ex situ corona poling process.

scholarly journals DESIGN OF TIRE PRESSURE MONITORING SYSTEM USING A PRESSURE SENSOR BASE

SINERGI ◽  
2019 ◽  
Vol 23 (1) ◽  
pp. 70 ◽  
Author(s):  
Lukman Medriavin Silalahi ◽  
Mudrik Alaydrus ◽  
Agus Dendi Rochendi ◽  
Muhtar Muhtar
Keyword(s):  
Monitoring System ◽  
Pressure Sensor ◽  
Electronic Device ◽  
Pressure Sensors ◽  
Pressure Level ◽  
Automotive Sector ◽  
Pressure Monitoring ◽  
Alert System ◽  
Tire Pressure ◽  
Tire Pressure Monitoring System

Currently, the Tire Pressure Monitoring System (TPMS) only monitors the condition of a tire pressure. However, there are no particular reactions taking place after the value of its tire pressure is discovered. In fact, the value of a tire pressure determines driving comfort and safety Therefore, this research proposed a method to integrate a TPMS and a Pressure Sensor Base (PSB) with a particular reaction required to fulfill tires automatically. The proposed TPMS has an electronic device unit directly attached to a tire’s valve. This unit includes pressure sensors, microcontrollers, Bluetooth transmitters and batteries. An alert system is generated whenever tire pressure exceeds the maximum or minimum safe pressure level. Moreover, if the pressure measured is below the lowest level of the desired pressure, it will automatically activate the compressor. Several experiments have been carried out to analyze the proposed system. The integrated TPMS has proven to be able to be an alternative tool for the automotive sector to keep maintaining the tires and to improve a driving comfort and safety.

Highly responsive screen-printed asymmetric pressure sensor based on laser-induced graphene

2021 ◽  
Author(s):  
Jiang Zhao ◽  
Jiahao Gui ◽  
Jinsong Luo ◽  
Jing Gao ◽  
Caidong Zheng ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Screen Printing ◽  
Large Scale ◽  
Low Cost ◽  
Pressure Sensors ◽  
High Sensitivity ◽  
Wearable Electronics ◽  
Integrated Sensor ◽  
Patterned Electrodes ◽  
Screen Printed

Abstract Graphene-based pressure sensors have received extensive attention in wearable devices. However, reliable, low-cost, and large-scale preparation of structurally stable graphene electrodes for flexible pressure sensors is still a challenge. Herein, for the first time, laser-induced graphene (LIG) powder are prepared into screen printing ink, and shape-controllable LIG patterned electrodes can be obtained on various substrates using a facile screen printing process, and a novel asymmetric pressure sensor composed of the resulting screen-printed LIG electrodes has been developed. Benefit from the 3D porous structure of LIG, the as-prepared flexible LIG screen-printed asymmetric pressure sensor has super sensing properties with a high sensitivity of 1.86 kPa−1, low detection limit of about 3.4 Pa, short response time, and long cycle durability. Such excellent sensing performances give our flexible asymmetric LIG screen-printed pressure sensor the ability to realize real-time detection of tiny body physiological movements (such as wrist pulse and pronunciation action). Besides, the integrated sensor array has a multi-touch function. This work could stimulate an appropriate approach to designing shape-controllable LIG screen-printed patterned electrodes on various flexible substrates to adapt the specific needs of fulfilling compatibility and modular integration for potential application prospects in wearable electronics.

scholarly journals Flexible 3D Printed Molds for Educational Use. Digital Fabrication of 3D Typography

2019 ◽  
Vol 15 (13) ◽  
pp. 4 ◽  
Author(s):  
Alejandro Bonnet De León ◽  
Jose Luis Saorin ◽  
Jorge De la Torre-Cantero ◽  
Cecile Meier ◽  
María Cabrera-Pardo
Keyword(s):  
3D Modeling ◽  
Low Cost ◽  
Digital Fabrication ◽  
3D Printer ◽  
School Environments ◽  
Flexible Material ◽  
Educational Environments ◽  
3D Printers ◽  
3D Printed ◽  
The Subject

<p class="0abstract"><span lang="EN-US">One of the drawbacks of using 3D printers in educational environments is that the creation time of each piece is high and therefore it is difficult to manufacture at least one piece for each student. This aspect is important so that each student can feel part of the manufacturing process. To achieve this, 3D printers can be used, not to make pieces, but to make the molds that students use to create replicas. On the other hand, for a mold to be used to make several pieces, it is convenient to make it with flexible material. However, most used material for 3D printers (PLA) is very rigid. To solve this problem, this article designs a methodology that allows the use of low-cost 3D printers (most common in school environments) with flexible material so that each mold can be used to manufacture parts for several students. To print flexible material with low-cost printers, it is necessary to adapt the machine and the print parameters to work properly. This article analyzes the changes to be made with a low cost 3D printer and validates the use of molds in school environments. A pilot test has been carried out with 8 students of the subject of Typography, in the School of Art and Superior of Design of Tenerife. During the activity, the students carried out the process of designing a typography and creating digital molds for 3D printing with flexible material. The designs were made using free 3D modeling programs and low-cost technologies.</span></p>

scholarly journals Classifying Degraded Three-Dimensionally Printed Polylactic Acid Specimens Using Artificial Neural Networks based on Fourier Transform Infrared Spectroscopy

2019 ◽  
Vol 9 (13) ◽  
pp. 2772
Author(s):  
Sung-Uk Zhang
Keyword(s):  
Neural Networks ◽  
Fourier Transform ◽  
Artificial Neural Networks ◽  
Thermal Degradation ◽  
Polylactic Acid ◽  
Fourier Transform Infrared ◽  
Ann Model ◽  
Flexible Material ◽  
3D Printed ◽  
Artificial Neural

Fused filament fabrication (FFF) is commonly employed in multiple domains to realize inexpensive and flexible material extrusion systems with thermoplastic materials. Among the several types of thermoplastic materials, polylactic acid (PLA), an environment-friendly bio-plastic, is commonly used for FFF for the sake of the safety of the manufacturing process. However, thermal degradation of three-dimensionally (3D)-printed PLA products is inevitable, and it is one of the failure mechanisms of thermoplastic products. The present study focuses on the thermal degradation of 3D-printed PLA specimens. A classification methodology using artificial neural networks (ANNs) based on Fourier transform infrared (FTIR) and was developed. Under the given experimental conditions, the ANN model could classify four levels of thermal degradation. Among the FTIR spectra recorded from 650 cm−1 to 4000 cm−1, the ANN model could suggest the best wavenumber ranges for classification.

scholarly journals 3D Printed Flowmeter Based on Venturi Effect with Integrated Pressure Sensors

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1509 ◽  
Author(s):  
Krzysztof Adamski ◽  
Bartosz Kawa ◽  
Rafał Walczak
Keyword(s):  
Liquid Flow ◽  
Pressure Sensors ◽  
Differential Pressure ◽  
Single Chip ◽  
Flow Meter ◽  
Modular Systems ◽  
Venturi Effect ◽  
3D Printed

In this paper we present a 3D printed flow meter based on venturri effect. Dimensions of the microchannels are 800 µm for wider and 400 µm for thinker channel. Application of different type of sensors was investigated: differential, absolute and digital barometer. Results of measurement of differential pressure and calculation of liquid flow are shown. Presented microfluidics device can be also easy adapted for modular systems. Presented flow meter is the first integration of commercial available sensors and 3D printed microfluidics structure in a single chip.

3-D Printing of Dielectric Electroactive Polymer Actuators and Characterization of Dielectric Flexible Materials

2018 ◽  
Author(s):  
David Gonzalez ◽  
Brittany Newell ◽  
Jose Garcia ◽  
Lucas Noble ◽  
Trevor Mamer
Keyword(s):  
Dielectric Material ◽  
Electrical Stimulus ◽  
Electroactive Polymer ◽  
Stress Strain ◽  
Active Structure ◽  
Flexible Material ◽  
Polymer Actuator ◽  
3D Printed ◽  
High Dielectric ◽  
Area Expansion

Dielectric electroactive polymers are materials capable of mechanically adjusting their volume in response to an electrical stimulus. However, currently these materials require multi-step manufacturing processes which are not additive. This paper presents a novel 3D printed flexible dielectric material and characterizes its use as a dielectric electroactive polymer (DEAP) actuator. The 3D printed material was characterized electrically and mechanically and its functionality as a dielectric electroactive polymer actuator was demonstrated. The flexible 3-D printed material demonstrated a high dielectric constant and ideal stress-strain performance in tensile testing making the 3-D printed material ideal for use as a DEAP actuator. The tensile stress-strain properties were measured on samples printed under three different conditions (three printing angles 0°, 45° and 90°). The results demonstrated the flexible material presents different responses depending on the printing angle. Based on these results, it was possible to determine that the active structure needs low pre-strain to perform a visible contractive displacement when voltage is applied to the electrodes. The actuator produced an area expansion of 5.48% in response to a 4.3 kV applied voltage, with an initial pre-strain of 63.21% applied to the dielectric material.

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