E-Textiles to Promote Interdisciplinary Education

Abstract

Electronic textiles (e-textiles) is a current research and development direction of the textile domain. As final applications, e-textiles may monitor human vital signs for sports and medicine, may extend garment functionality for entertainment, or ensure electromagnetic compatibility (EMC) using flexible textile shields. However, this book chapter focuses on a certain aspect of e-textiles, namely, their role in promoting interdisciplinary education. E-textile products are the result of material science, physics, mathematics, mechanics, electronics, and more recently of software and Artificial Intelligence (AI). This was the rationale for initiating three Erasmus+ projects in the field of e-textiles to foster interdisciplinary training for students and young professionals. The new educational materials tackle the relation between Science Technology Engineering Mathematics (STEM) disciplines of the official curricula and some of their final applications, such as e-textile prototypes. The educational materials are conceived in a problem-based learning (PBL) approach. The presented examples encompass fabrics with inserted metallic yarns and metallic coating for electromagnetic interference (EMI) shielding, pressure sensors, and related electronic data processing, as well as virtual prototyping of Radio frequency (RF) suits. EMC is tackled from an educational perspective.

1. Introduction

Electromagnetic compatibility (EMC) and e-textiles domain reach a common ground by a specific application, namely, electromagnetic interference (EMI) shielding fabrics with electrically conductive elements. The textile shields may be manufactured either by inserting metallic yarns into the fabric structure or by coating the fabric surface with metallic particles. Many research and development solutions in this field are available because textile fabrics are lightweight, flexible, and with good mechanical resistance [1, 2, 3, 4, 5, 6, 7, 8, 9]. However, this book chapter tackles EMC from an educational point of view: EMC knowledge was applied in e-textile applications within the educational modules of three Erasmus+ strategic partnership projects. This book chapter presents learning of EMC via e-textile applications. The methodology applied for this book chapter presents the educational modules of the three projects from a triple perspective: the interdisciplinary character, the EMC prototypes for educational purposes, and the problem-based learning (PBL) approach. The implementation of the Erasmus+ projects encompass a duration of 8 years: 2018–2025. A substantial impact could already be achieved amongst students and young professionals using the prepared educational materials.

2. The EMC dimension of e-textiles

E-textiles have numerous applications for the EMC domain. One of the most widespread applications is the electromagnetic shielding of radiation using electric conductive fabrics, according to Faraday’s physical principle. Because fabrics are lightweight, flexible, and with good mechanical resistance and air permeability, they may successfully replace metallic plates for shielding enclosures. By shielding radiation, the health of living beings is preserved, as well as the proper functioning of electronic equipment, either against susceptibility or emissions risks [9].

Two main technologies for imparting electric conductive properties to fabrics apply as follows: inserting metallic fibers/yarns into the fabric structure and coating via various methods, such as dip coating, doctor-blade coating, magnetron plasma coating, and others. The National R&D Institute for Textiles and Leather, INCDTP – Bucharest has contributed to this research topic: The electromagnetic shields were manufactured by combining both technologies (inserting metallic yarns and plasma coating with metallic layers). An attempt was also made to model the electromagnetic shielding effectiveness (EMSE) of these textile shields in relation to their significant electric and geometric parameters, based on the impedance method and its derivate relations [10]. Moreover, a web application was programmed in PHP, based on the deducted analytical relations to support designers of textile enterprises in the manufacturing of textile shields [11]. The manufactured shields were tested according to standard ASTM ES-07, via transverse electromagnetic (TEM) cell.

Figure 1 shows EMSE on a logarithmic diagram in the frequency range of 0.1–1000 MHz for a woven fabric with inserted silver yarns in warp and weft at a 4 mm distance and the same fabric with copper magnetron plasma coating of 1200 nm.

Figure 1.

a) EMSE diagram of textile shields. b) Fabric with silver yarns. c) Fabric with silver yarns and copper coating.

The document provided by [FTTS-FA-003] states the shielding ranges in dB for textile shield performance evaluation meant for professional (Table 1) and general use (Table 2) [12].

Grade	5; Excellent	4; Very good	3; Good	2; Moderate	1; Fair
EMSE range	EMSE>60 dB	60 dB ≥ EMSE >50 dB	50 dB ≥ EMSE >40 dB	40 dB ≥ EMSE >30 dB	30 dB ≥ EMSE >20 dB

Table 1.

Class I – Textiles for professional use.

Grade	5; Excellent	4; Very good	3; Good	2; Moderate	1; Fair
EMSE range	EMSE>30 dB	30 dB ≥ EMSE >20 dB	20 dB ≥ EMSE >10 dB	10 dB ≥ EMSE >7 dB	7 dB ≥ EMSE >5 dB

Table 2.

Class II – Textiles for general use.

The textile shields manufactured by our team may be classified as “very good” in the frequency range of 0.1–100 MHz and “good” in the frequency range of 100–1000 MHz for professional use and “excellent” for general use.

Besides textile covers, tarpaulins, or sheets for shielding EM radiation, a significant application of e-textiles and e-fabrics is the RF suits for specialists working at high-power antennas. E-textile fabrics may be used either as protection for electronic equipment within BUILDTECH products or as protection clothing for workers at high-power EM fields within PROTECH products (classification of technical textiles according to TechTextil, https://techtextil.messefrankfurt.com/frankfurt/de.html). Virtual prototyping software for clothing supports to develop customized RF suits. Moreover, sensor data of smart textiles is often transmitted via antennas and further processed by PC hardware; this process is also related to EMC. This book chapter intends to present EMC and e-textiles as educational support in preparing students.

3. Methodology

The smart and e-textile prototypes represent an excellent means to use various basic disciplines, such as material science, physics, mathematics, mechanics, electronics, and informatics. This is why e-textiles may connect students to the basic theoretical disciplines and provide touchable prototypes. Some of the e-textile applications are for the EMC domain: RF shielding suits, EMI shielding fabrics, and smart textiles with sensors and data processing. Moreover, the PBL approach is a modern method to prepare trainees for real-life technical problems [13, 14, 15, 16]. To systematically present the educational materials of the three Erasmus+ projects, a specific methodology was applied. All these three projects were analyzed following three criteria:

• Interdisciplinary character

• E-textiles and EMC prototypes

• Problem-based learning approach: from practice to theory

The synthetic methodology and its key points are presented in Table 3.

Project/consideration	A. Interdisciplinary	B. Prototypes	C. PBL approach
1. Skills4Smartex	Structured on four basic STEM disciplines: maths, physics, material science and ELTH	Electric conductive fibers, yarns, fabrics, design of e-textiles, data processing and testing	The 28 educational modules from prototypes to theory (SMART to STEM)
2. OptimTex	Software tools based on FEM for weaving, knitting, virtual prototyping, embroidery, design of experiments	Embroidered e-textiles with different functionalities and EMI shielding fabrics	The explanation of 28 practical examples by means of related theory and application
3. DigitalFashion	Software algorithms to address five databases: fabrics, garments, styles, avatars and knowledge base	Virtual prototyping of a technical textile PROTECH article: RF suit	The educational modules for training on the virtual prototyping online platform

Table 3.

Methodology for presenting the outcomes of the three projects.

The main data on the three Erasmus+ projects containing the title, call, duration, and website is presented in Table 4.

Acronym	Title	Type, call	Duration	Website
Skills4Smartex	Smart textiles for STEM training	Erasmus+, VET, strategic partnerships	2018–2020	www.skills4smartex.eu
OptimTex	Software tools for textile creatives	Erasmus+, HED, strategic partnerships	2020–2022	www.optimtex.eu
DigitalFashion	Collaborative Online International Learning in Digital Fashion	Erasmus+, HED, strategic partnerships	2022–2025	www.digitalfashionproject.eu

Table 4.

Data on the three Erasmus+ projects.

Each of the presented fields in the table is going to be described in detail within this book chapter. The last section will be devoted to the impact achieved towards the target group of trainees.

4. Contents

4.1 The interdisciplinary character

The interdisciplinary character of the educational materials is given by the interconnection amongst the various basic disciplines, underlined by the specificity of smart and e-textiles.

4.1.1 Skills4Smartex

The educational modules of Skills4Smartex tackle four basic STEM disciplines with applications in smart textile prototypes. These basic disciplines are as follows:

• Mathematics

• Physics

• Chemistry and material science

• Electrotechnics

Each technological aspect of manufacturing smart textile prototypes is described by these four basic disciplines. The presented technological aspects are as follows:

• Novel fibers and yarns, materials and methods, virtual prototyping, smart textile design, smart textile prototypes, data processing, and new methods for testing smart textiles.

Another criterion of structuring the modules is related to the direction of teaching:

• From basic disciplines to practice of manufacturing smart textile prototypes: STEM to Smart

• From smart textile prototype construction to the basic disciplines: Smart to STEM

The 56 modules were conceived in a matrix structure of 2 × 7 × 4 = 56 modules (Figure 2).

Figure 2.

The matrix structure of the interdisciplinary modules.

Having in view the matrix structure of the educational modules, an e-learning instrument was conceived and programmed in PHP, with a filter including drop-down lists for each criterion. The e-learning instrument is available online on the project’s website with the URL address: http://skills4smartex.eu/instrument.php.

A print screen of the web instrument depicts its envisaged application (Figure 3):

Figure 3.

Print screen of the online e-learning instrument with the filter.

This concept was applied for the trainees to see that the basic disciplines are interconnected and they are tackling each particular aspect of manufacturing smart textile prototypes. Each educational module has about 15–20 pages with text and images and is focused on the specific application of the basic discipline applied for smart textiles.

Mathematics presents, for instance, the relations of computing fiber’s and yarn’s linear density, the mean fiber length, the tensile stress, and the elongation at break, as well as the Young modulus and the tenacity. Mathematical expressions such as ratios, weighted averages, and percentages are used. Percentage expressions were also used to compute the take-up and crimp of woven fabrics, whereas trigonometric expressions were used to model the yarn trajectory within woven fabrics. Specific triangulation relations are given for constructing virtual humans and 3D human body models via scanning. Other mathematical geometrical considerations related to 1D, 2D, and 3D objects, as well as mathematical relations related to the optics in the design of smart textiles, are presented. Nonetheless, more advanced statistical processing relations, such as the moving average and the quartile for assessing acquired data from smart textile sensors, are presented.

Physics concepts and their relations are usually theoretically introduced by their corresponding physical process in a logical sequence of operations. The physics modules of Skills4Smartex are adapted in relation to the manufacturing of smart textiles, showing the mathematical relations applied and the meaning of the physical processes. Introducing physics phenomena from a theoretical point of view usually follows a certain logical pathway related to the interconnection of quantities. For instance, in electrotechnics, the electric charge is first introduced, and afterwards current intensity and current density, intensity of the electric field and voltage, power, and so on. Each quantity has a specific mathematical relation in connection to the previously introduced physical quantities. The aim of the Skills4Smartex modules was to follow the logical path of introducing the physical quantities and their mathematical relations in view of the practical work of manufacturing smart textile prototypes.

The chemistry modules present the material science aspects of smart textiles starting from raw materials of fibers and yarns up to the woven and knitted fabrics and up to the manufacturing of prototypes, data collection, and testing.

The electrotechnics (ELTH) modules present the basic notions of electricity applied to smart textiles. Computations for designing an electric circuit with metallic yarns, LEDs, and batteries within a smart T-shirt are presented and notions, such as the skin depth in metallic yarns, are introduced, which are theoretically related to EMC. Other ELTH modules introduce digital electronics applied to smart textiles, communication via Arduino boards, data collection, and processing.

4.1.2 OptimTex

The OptimTex modules are focused on the specific software for the design of textile materials and have four main technology chapters and added one statistics and one economy chapter as follows:

• Design and modeling of woven structures

• Design and modeling of knitted structures

• Design and modeling of garments by 3D scanning software and CAD/PDS software

• Design and modeling of embroidered structures

• Software for the design of experiments

• Guide regarding technology transfer of textile software solutions into the industry

The interdisciplinary character is given by the explanations of using the finite element method (FEM) software for the design of textile materials and the various material properties, which have to be introduced into the software for this purpose.

The module for the design and modeling of woven structures describes basic software, such as TexGen, but steps further to describe software, such as ArahWeave and Abaqus, for designing 3D woven structures. The module for the design and modeling of knitted structures describes the M1 Plus software from STOLL company in the manufacturing of knitted fabrics with normal loops, modified loops, spacer fabrics, and 3D-shaped fabrics. The module for design and modeling garments provides four examples of 3D human body scanning using 3D photogrammetry, 3D human body modeling and reconstruction, construction of a kinematic 3D body model, and 3D virtual prototyping of personalized smart garments, and thus, displays the entire process for the needs of 3D virtual prototyping of individualized garments. The design and modeling of embroidered structures are focused on the embroidery of metallic yarns on textile substrates to produce e-textiles: textile-based heating elements, illuminated fabrics, or textile-based water leak sensors. The module on the design of experiments tackles statistics applied to technical and smart textiles in the preparation of physical experiments. The main aim is to reduce the number of physical experiments, having in view sufficient insights on data and response surface modeling. Finally, the guide for TechTransfer tackles the modalities to introduce the knowledge of software into practical work within industry textile enterprises.

4.1.3 DigitalFashion

The DigitalFashion project is focused on educational materials for the virtual prototyping of clothing. The main result is an online training platform. Most software for virtual prototyping are available as desktop applications and can be quite expensive. The training platform will be available online for students and professionals starting in September 2023 at the URL: http://digitalfashionproject.eu/?page_id=2260. The training platform uses five relational databases: fabric database, garment database, fashion database, 3D human avatars database, and a knowledge base for interconnection. The educational modules encompass the steps of clothing design with the support of the training platform. They combine textile technology, material science, informatics, and e-learning.

4.2 The focus on E-textiles prototypes

E-textiles or smart textiles are a current trend in modern textile products, also known as wearables [17]. They usually combine textiles and electronics, and their manufacturing was possible with the advent of the spinning of metallic fibers and yarns and with the miniaturization of electronic components. E-textiles may integrate various electric/electronic circuits and components, such as sensors, actuators, or antennas and are available on different levels: passive, active, and self-regulated.

4.2.1 Skills4Smartex

The educational modules of Skills4Smartex are specifically conceived to describe the manufacturing of smart textile prototypes. On the one hand, it is presented how the basic disciplines contribute to the design of smart textile products; on the other hand, a prototype is described related to its components of basic disciplines.

Several prototypes are described, such as the integration of a basic circuit with battery, conductive wires and LEDs into a T-Shirt, a pressure sensor integrated into a pillow and powering an LED, and the same pressure sensor integrated into a smart sole using Arduino communication in detecting walking profiles (Figure 4). The principle of the textile pressure sensor and its practical manufacturing are presented in Figures 5 and 6. Two conductive layers close an electric circuit at pressure.

Figure 4.

Smart e-textile insole.

Figure 5.

Principle of the textile pressure sensor.

Figure 6.

Manufactured pressure sensor prototype.

All prototypes had educational character, and some types were manufactured by high school students in workshop sessions.

4.2.2 OptimTex

The OptimTex educational modules were focused on the design and modeling of technical and smart textiles. The dedicated module of embroidery of metallic yarns on textile substrates followed specifically the manufacturing of smart textile products, such as a textile-based heating element, illuminated fabrics, or water-leakage sensors (Figure 7).

Figure 7.

Concept and realization of an embroidered water-leakage sensor by University West Bohemia (www.fel.zcu.cz).

The module on the design of experiments presented an experimental plan for manufacturing a textile shield for protection against electromagnetic interference (EMI). Two independent parameters were chosen, namely, the thickness of the magnetron plasma copper coating and the yarn’s density of the coated fabrics. The result variable was the electromagnetic shielding effectiveness, measured via a TEM cell, signal generator, power amplifier, and oscilloscope.

Figure 8(a–c) presents the: magnetron plasma equipment of the National Institute for Laser, Plasma and Radiation Physics, INFLPR – Magurele – Bucharest (www.inflpr.ro), and the TEM cell scheme and experimental setup of the National Institute for R&D in Electrical Engineering, ICPE-CA – Bucharest (www.icpe-ca.ro). Figures 9 and 10 present the technical textiles using inserted conductive yarns and plasma coating meant for EMI shielding.

Figure 8.

a. Magnetron plasma equipment cell experimental setup, b. TEM cell scheme, and c. TEM.

Figure 9.

Woven fabrics with inserted metallic yarns and different fabric yarn densities.

Figure 10.

Same woven fabrics with inserted metallic yarns copper plasma coating.

Results of EMSE had values of 45–55 dB in the frequency range of 0.1–100 MHz. More details in Ref. [18].

4.2.3 DigitalFashion

The modules of DigitalFashion are focused on virtual prototyping of clothing, which are also meant for technical textiles of type PROTECH (according to TECHTEXTIL fair classification https://techtextil.messefrankfurt.com/). In this regard, the design and the fitting of an RF suit for professionals working at high-power antenna maintenance may be easily done via virtual prototyping software (Figure 11).

Figure 11.

RF suit made by virtual prototyping.

The pattern was constructed with dual front breast pockets, heavy-duty double flap zipper, boot, and hand loops to keep the suit secured in place for added operator safety and convenience. The suit is designed with belt loops for additional devices and has double interior pockets for storage. Strong triple v-stitching throughout ensures durability and longevity. This suit is made with a cotton construction that offers excellent body protection and breathability. Elasticated cuffs and ankles, hand webbing, heel loops, and double kneepad pockets provide added comfort and convenience. The yarn had a specific composition of 41.8% cotton fiber, 32.1% polyester fiber, and 26.1% metal fiber. The stainless-steel fiber with ion precision quenching technology is blended with cotton fiber and polyester fiber. It has good resistance to washing, air permeability, and EMI shielding properties.

The RF suit was designed as an application for virtual prototyping of clothing for the EMC domain. Virtual prototyping software enables the fitting of a garment on a human avatar without physical manufacturing, faster time-to-market cycles, and integration of the entire production chain.

4.3 PBL approach

The problem-based learning (PBL) approach is a modern educational concept, in which learning starts with a practical session of solving a real problem. Classical teaching usually starts with presenting the theory, making some applied exercises, and finding some applications. The PBL approach is especially trendy nowadays because it enables practical working, confrontation with real problems, and their specific solving [13, 14, 15, 16].

4.3.1 Skills4Smartex

The 56 Skills4Smartex educational modules are divided into two main categories as follows:

• 28 modules from STEM to Smart: from theoretical disciplines to practical manufacturing

• 28 modules from Smart to STEM: from practical manufacturing to theoretical disciplines

The Smart to STEM modules are focused on the practical manufacturing of smart textile prototypes. The modules present the prototype and the design problem to be solved. The modules are further related to the textile technology step and the basic discipline (maths, physics, material science, and ELTH). More details on the online available e-learning resource: http://skills4smartex.eu/instrument.php.

4.3.2 OptimTex

The OptimTex educational modules are conceived in the PBL approach, from practical examples up to theory, applications, and self-assessment quizzes. Because this structure is applied to all modules, an e-learning instrument was programmed in HTML5, PHP, and JavaScript to enable quick and intuitive access to educational resources. Figure 12 presents a print screen of the e-learning instrument, available with free access at the URL: http://optimtex.eu/instrument.php.

Figure 12.

Print screen of the OptimTex e-learning instrument with PBL structure.

There are altogether 28 examples of the following six modules:

• Design and modeling of woven structures

• Design and modeling of knitted structures

• Design and modeling of garments by 3D scanning software and CAD/PDS software

• Design and modeling of embroidered structures

• Software for the design of experiments

• Guide regarding technology transfer of textile software solutions into the industry

Each example includes the related theoretical aspects, the specific software applications, and four multiple choice tests for self-assessment. The multiple choice tests were transformed into HTML by the HotPotatoes software. This e-learning instrument is available with open, quick, and intuitive access on the project’s website: www.optimtex.eu, TAB Instrument. Google Analytics showed high access to the instrument and feedback questionnaires, proving the high interest of students and professionals in using the instrument. The PBL approach was adapted by this structure of the modules.

4.3.3 DigitalFashion

The educational modules of DigitalFashion are conceived in relation to the design process of a garment and the DDL design page of the online training platform.

The DDL page stands for the Digital Design Learning page of the training platform and enables garment fitting on human avatars (Figure 13). Thus, training in DigitalFashion is based on practice using virtual prototyping of clothing on the online platform for higher education students and young professionals from the industry.

Figure 13.

The DDL page of the online training platform.

5. Impact

Several virtual and physical training courses were organized within the first two projects. Three intensive study programs (ISPs) were organized during the OptimTex project: one virtual and two physical. Students and lecturers from four European universities participated in each training event (Figures 14–16).

Figure 14.

Image from the virtual ISP hosted by technical University of Iasi.

Figure 15.

Image from the physical ISP hosted by University of Maribor.

Figure 16.

Image from the physical ISP hosted by Ghent University.

The students were especially impacted both by the lectures and the e-learning instruments. Google Analytics showed the following figures of accesses during March–October 2022: 246 users, 226 new users, average engagement time: 1 m 16 s, views: OptimTex website: 876/OptimTex instrument: 181. Feedback questionnaires had maximum scores for e-learning interaction and practical training using software in textile design and fewer scores for matching the course using their study field [19].

6. Conclusions

This book chapter tackles EMC from an educational point of view. It is meant to show how the interdisciplinary field of EMC and e-textiles contributes to the learning process. The educational materials were conceived using the PBL approach, and specific applications between EMC and e-textiles were highlighted. The educational materials achieved a high impact on students in three ISPs within the Erasmus+ OptimTex project.

Acknowledgments

These projects were funded with the support of the European Commission. Publishing was funded by the Ministry of Research and Innovation, by Program 1—Development of the National System for R&D, Subprogram 1.2—Institutional Performance—Projects for Funding Excellence in R&D&I, contract no. 4PFE/30.12.2021.