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Thin multilayered PVDF based piezo co-polymer for Textile Integrated Intelligent Wearable Self-sustained monitoring and safety applications in garment and footwear

Final Report Summary - TIIWS (Thin multilayered PVDF based piezo co-polymer for Textile Integrated Intelligent Wearable Self-sustained monitoring and safety applications in garment and footwear)

Executive Summary:

The TIIWS Project attempts to introduce intelligence in everyday products, according to a well-established research and new product development trend. Main objective of the Project is to integrate advanced polymers with piezoelectrical and electrostrictive properties in textiles, in order to develop advanced products, garments and footwear, to be applied for safety, sensing and monitoring applications.

The technology development is based on preliminary results available within the hi-tech SME PIELLE, and is enabled with the external support of the material supplier SOLVAY SOLEXIS. The approach is to exploit functional materials that can be fused within the products, which act as sensors or harvester of Energy while absolving their functions (garments and shoes).

The innovation associated with TIIWS Project run in the direction of overcoming the lack in integration of the sensing elements into smart products, their lasting and the quality of response to stimuli. The products and associated business generated are relevant for the strong impact at European level in smart products, and to develop knowledge relevant to implement the concepts into advanced systems and products in diverse technical fields.

S/T Objectives are related to the Polymer adaptation, poling and integration with textile substrates, application into garment and footwear systems and their validation in real products. In particular:

• Innovative PVDF-based materials: the materials will be developed following different lines of research, already started and preliminarily implemented by the PIELLE, in terms of:

o Polymeric electrical poling, supporting coupling with different substrates, structural integrity and surface compatibility with the polymer substrate, electrical conduction and thin layer deposition;
o Design of the process and the integration with the textile production chain;
o Layered design of the material achieving micro-structure compliant with the movements, relevant for the energy transformation and adequate levels of potential and current for the specific applications and the typical deformation and motion fields.

• Design of the material active system: innovative piezo-material will be exploited to design and develop an active system capable to give response to stimuli during its use.

o Integration of the active materials coupled with substrates into products conceptual design, its shaping and three dimensional arrangement in order to comply to the end use applications;
o Development of peculiar shapes, structural ad-hoc concepts and structures, conformal applications and compliant structures for the maximization of the energy coupling at structure level, already implementing the final product design and the definition of the expected movement, deformation and structural issues;

• Integration into textile products: the active system will be integrated into textile-based garment and footwear components, providing the achievement of advanced intelligence into everyday products.

o Materials production at batch and large scale level, to be developed within the frame of activities of PIELLE. The capability of the fabric to be assembled and laminated onto the samples, of the poling elements (conductive layers) to be connected to junctions and mutually insulated, and of the multilayer structure to be developed in one assembly are the topics of research;
o Integration of the design of the system into the products, smart production methods and customized solutions. The activity of development will be basically oriented to grant the compliance at fabric level, and up to the garment and footwear production methodology;
o Garment design taking into consideration the electronics embedded (storage, calculation, external communication) and the production constraints;
o Footwear design, taking into consideration the integration of the systems and the typical constraints of the footwear sector.

Project Context and Objectives:

Main objective of the Project is to integrate advanced polymers with piezoelectrical and electrostrictive properties in textiles, in order to develop advanced products, garments and footwear, to be applied for safety, sensing and monitoring applications. Project is based on the experience of the Partners involved in a comprehensive value-chain. Overall Project Objectives are related to the Polymer adaptation, poling and integration with textile substrates, application into garment and footwear systems and their validation in real products.

The TIIWS Project attempts to introduce intelligence in everyday products, according to a well-established research and new product development trend. The approach is to exploit functional materials that can be fused in invisible way within the products, which act as sensors while absolving their functions (garments and footwear). The innovation associated with TIIWS Project run in the direction of overcoming the lack in integration of the sensing elements into smart products, their lasting and the quality of response to stimuli.

The progress introduced within TIIWS Project is such that the exclusive technologies developed and available within the hi-tech SME PIELLE with the external support of the material supplier Solvay Solexis S.p.A. is furthered into products providing concrete advancement to the whole partnership of the SMEs covering the whole manufacturing value-chain: LUSI for the garment and JGH for the footwear.

The products and associated business generated are relevant for the strong impact at European level in smart products, and to develop knowledge relevant to implement the concepts into advanced systems and products in diverse technical fields.

The activities performed since the beginning of the project, and in particular the latest achievements in the second period were focused on two main fields of technical development actions:

- active material processing and performances evaluation, including all the steps needed in order to transform the raw polymer into an active element, suitable for being implemented into a textile composite assembly
- active system design and development, adaptation of the system to the different types of end use, design of the product and implementation within a production chain

Technical activities have been backed by non – technical activities oriented to ensure the maximum visibility and resonance to the project, concerning dissemination, IPR management and exploitation, establishment of an online collaborative platform.

From the side of material development and performances evaluation and adaptation, the activities that in the first period have been run in close collaboration with raw polymer supplier SOLVAY SOLEXIS and finalized to ensuring the best material to be available, have been focussed on the transformation of the polymer, organized in three steps: tape drawing, deposition of electrodes and poling under electrical field. Such activities have been performed mainly by RTD performer DAPP, in collaboration with the hi-tech SME partner PIELLE.

The design of the system, its integration within the footwear and garment and the implementation of the product in accordance to the typical production constraints and facilities brought to the development of sustainable design for potential products to be implemented in accordance to the technical development and capabilities of the active part of the system. In particular:

- PIELLE and LUSI exploited their know how to integrate the system within garments, being supported by DAPP for the integration of the materials and the adaptation of the production methods with the constraints of the materials, in particular associated to the coupling process and the thermal – mechanical solicitation of the active material, with the necessary protection from the external environment, maximizing the transformation of motion into energy
- JGH adapted their product to integrate the system within footwear, with the strong support from INESCOP in terms of concept of integration of the system in the shoe system and in the production methods, giving relevance to the ergonomics and the efficacy of motion transformation into signal

Thanks to the concurrent development of materials and products, the conceptual design activities have led to pre-series prototypes that can provide a relevant transformation of the motion into energy, exploited either for the generation of signal, to be collected and stored for motion recognition, storage and interpretation of movements, and local generation of energy finalized to enhanced visibility of the wearer. Such activity is backed by a Design support Tool, available online and released on the TIIWS private website, aiding the designers in the development of products starting from specifications and required performances.

Dissemination activities: the consortium participated in relevant activities of dissemination of TIIWS project, in the framework of textile-related events, presenting the project into European level fairs and events, constantly updating the website in technical and dissemination contents.

IPR management and exploitation: the consortium SMEs have closed an IPR agreement, stating the boundaries of the exploitation of the three main results, as specified in the relevant final Plan for Exploitation of Knowledge. In particular, the central role of PIELLE and the support from the products developers and integrators JGH for the footwear and LUSI for the garments is clarified, also in terms of the medium term exploitation and market opening strategy.

The accomplishment of the S&T Objectives can be verified against specific technical indicators, characterized by precise and quantifiable meters. The evaluation of the achievement has been performed during the Project duration, with special attention against the respect of the milestones which are linked to single objective. A large part of the testing and performances evaluation was performed in the framework of testing and validation, performances evaluation and Modelling, ensuring a higher level of confidence for the results to be achieved. The validation methods for the achievement of each S/T objective, associated to the specific technical barriers expected against their achievement, can be summarized per the following items:

- Innovative materials: The achievement of performances has been measured in laboratory scale, during the different phases of the development of materials. A large part of the efforts have been paid during this fundamental phase, especially towards the achievement of sufficient repeatability in the samples production and testing procedures execution. The step-forward innovative content of the samples developed, in particular concerning the intimate integration between polymer layer, electronic components and textile/protection layers, made it not significative to base trials evaluation on comparisons with analogous existent products which are all actually based on completely different piezoelectric technologies. Therefore a step-by-step approach for the validation of the different classes of parameters has been followed, tracking advancements and achievements in the performances obtained and enabling full control over the Project results and the progress
- Design of the Material Sensing Systems: The concepts developed within the intermediate design and product development phases have been validated against ergonomic models and in simulated environment. The availability since the early beginning of active materials mock-ups enabled the real-scale testing and evaluation of the application features under conditions simulating the use, and therefore a wiser design of the integrated sensor systems and of the components oriented to the use
- Integration into Smart Products: The validation of the prototypes has been conducted against the practical results achieved for their production and testing in use conditions, considering all the relevant aspects affecting the product realization. Manufacturing aspects: the production chain has been conceived to be compliant with the expected simplicity and economics of production, considering the highest level of performance as the main driver in the first part while leaving more room to process economies in the final steps (confectioning). The final product functionality have been also evaluated against end-users needs such as “wearing comfort” and “invisibility”, mainly verifying that suitable ergonomic solutions had been implemented such as active system protection (shocks, scratches, weather), maintenance (washing cycles), body response (positioning with respect to the body).. Performances reliability and reproducibility within acceptable limits have been checked against the use results, verifying the functionalities of the prototype and assessing its scalability.

Project Results:

In accordance to the DOW, and with the final plan for IPR exploitation subscribed from the SMEs partners, the following three results / foregrounds are identified:

- Innovative Integrated textile Composite Materials
- Design of the Material Active Systems
- Integration into Smart Products

Result 1: Innovative Integrated textile Composite Materials

The first innovation is the scientific knowledge related to the processing and characterization of the multilayered composite textile-based piezoelectric material developed. The composite material is based on the piezopolymer supplied by SOLEXIS, which chemical composition has been optimized from SOLEXIS to ensure the maximum performances. The composite active material (single- or multi-layered) is comprised of well defined functional layers (active polymer, electrodes, protective and insulation layers). Adequate pre-processing has been developed in order to provide the required performances: the definition of the processing parameters needed to optimize final performances is the core part of this innovative result, for the tape formation, the poling and the electrodes deposition steps. Main impact of this result is connected to the increasing of piezoelectric polymers performances, enabling innovative design for smart applications based on flexibility, improved durability, higher reliability and power generation, and overcoming limitations of traditional piezomaterials. The key understanding and development effected from the TIIWS partners during the execution phase of the project is associated to the processing of the polymer. In particular, the casting has shown a relevant limitation, for the constraints in the production and the high costs related to the white room operations. The tape extrusion and drawing process has been therefore tested and successfully evaluated for the process of the raw polymer under test. The step of electrodes deposition has been performed thanks to serigraphic application, exploiting a current trend in deposition of conductive paths on a flexible substrate for medical applications, successfully transferred to permit a surface charge collection. The deposition of conductive layer is furthermore necessary preliminary step to the poling process, deployed on a custom-made machine able to generate a rated field (voltage up to 30 kV) and to transmit to the sheets in a totally safe and reliable-reproducible way.

The whole processing of the material to transform into the key starting point of the system showed points of strength, related to the reliability of the materials and their mechanical resistance. Still, the process of extrusion, as conducted in a lab-scale mill, showed limitations associated to the surface finishing of the tape, which could be enhanced with a special die (superfinishing and super-hard material of the extrusion hole). This let a further work to be identified for the future steps and development / industrial implementation of the TIIWS project.

Result 2: Design of the Material Active Systems

This innovative result is the knowledge connected with the performance provided by the active system developed, enabled by its specific design, and its functional use. Final application involve function of sensing, self-monitoring, actuation or energy generating/harvesting device.

The processing of the poled material into a system potentially implementable within a product has been key to the development of a real scale product, in particular embedding the virtual prototyping and modelling assisted concepts. In particular, two methods are identified to increase the output power of the system: the increase of the actuation frequency and the increase of the active polymer volume (through multi-layered assembly). Therefore, aerodynamic concepts are applied to the different solutions, for garment and footwear, exploiting the apparent air velocity in particular for sports applications.

For each specific use, the proper selection of design and tailored performances, embedded within the Design support Tool instrument developed and implemented within the project private webspace, representing as well fundamental content of this innovative result. Fundamental impact is related to the development and validation of innovative piezoelectric systems, to be operable fully integrated into textile substrates, representing a step forward for smart materials design and capabilities, enabling possible new application. Further impact is also linked to the opening of new market perspectives, based on possible exploitation of the active system capabilities also outside of the main target markets, garments and footwear, that remain currently the main fields of development. For this reason the testing has been conducted at the level of the raw materials, at the level of the system, and also at the full product level, for which substantial perspectives for developments and integration still exist, in reason of the freedom to fantasy and implementation into different segment this system unlocks.

Result 3: Integration into Smart Products

The third innovative result is the knowledge related to the design and manufacturing of the final products, developed into conceptual design and a small series of pre-prototypes. Products are based on the integration of the active system into garments and footwear for different applications, and tested for performance validation, according to different types of final functionalities and the purpose of added-value of the product (the market is willing to pay in order to have the functionality embedded).

Impact of this result is linked to new product and market opportunities for the SME participants, enabling new multifunctional products to be launched in the garments and footwear sector, potentially offering possibilities to increase end-users market shares.

Also at the level of product the results are positive: optimal level of integration of the active system into garment and footwear has been proven, satisfying critical aspects like ergonomy, durability, maintenance, and enabling the full potential of the previous results 1 and 2 to be expressed. Prototypes of high visibility jacket, active muff, active footwear, sensing soles and insoles have been produced and validated against user-centered criteria (design, ergonomy, comfort). These results paved the way for future exploitation actions, to which SME partners are already fully committed.

Potential Impact:

TIIWS Project is focussed on the introduction of advanced technology into simple everyday products, involving innovative stimuli sensitive and energy harvesting materials, design methodologies and integrated production methods, for increasing the level of intelligence of wearable products, with the final purpose of increasing the safety of the wearers. The progress beyond current state of the art is significant, due to the fact that no current materials and products do provide multifunctional sensing capabilities within such a deep integration between the product and the active material.

To understand the dimension of the TIIWS impact, it is worthwhile to identify the expected effects related to introduction of the product on the market, and the associated Economical, Safety and Strategic dimension at European level related to the achievement of target results.

Economic-competitiveness impact

According to the breakdown of the costs associated to the prototyping, the level of production, and the results of the project development, addressing the materials with the current productions steps and the integration of the systems into the products, involving the different actors in the value-chain, the competitiveness for the products to be developed appear strongly dependent on the impact of the quality control and the Product integration. Key element is associated to the extrusion process.

These last items are expected to be less relevant as high the number of items produced can be raised, enabling the adoption of automated production and reducing the intervention necessities for workers. According to a three steps development, the impacts of integration are expected to be lowered up to reaching a commercial level:

- First step of integration, hand assembly and single item quality check, reached at the end of the Project. The repetitive operation costs are not absorbed by any type of automation, any product has to follow own process. Costs are additive, estimate of high labour intensity per apparel item, in the order of 75€. According to the projections at the end of the project, such costs seem to be respected within the tape drawn and the process in a manual integration;
- Second step of integration, some parts are automated (as the gluing and assembly, moulding into purpose developed moulds having multiple injection points for the footwear, automated knitting and integration of the material into the substrate) the operator has the responsibility to follow the line and implement the electronic systems, with a much lesser effort and the application in activities with a lesser impact on the final quality of the product, which can be estimated around 25€ - 40€ per item (or pair in the case of shoes);
- The third step accounts for total automation of the production process, leading to an automated assembly of the items. In reason of the volumes sold such a step can only be reached as the volumes are worth it: costs per item can become marginal, in the order of 1 to 5 €, and the requirements for testing and checking product quality enter into conventional industrial processes. The expected costs are related to automated process control, already integrated within the line, and spread over a large number of products. The number of items produced needs to be higher than 10.000 per year, according to scale economy principles, to ensure scale profitability.

Exploitation routes are identified as per the different steps accordingly, and preliminarily set in the IPR agreement bounding the SMEs participant.

Expectations and business plans concerning the implementation of the TIIWS project are currently under elaboration from the SMEs, and need to be treated with confidentiality. According to the different projections, a ROI can be expected in not later than 4 years.

Safety and Social Impact

TIIWS Project final aim is to produce active garments – shoes that, thanks to the performances attained by the polymeric piezo materials and the advanced design concepts, can provide a superior level of safety to the wearer.

Simple properties and technological capabilities, like the possibility to provide a signal under different mechanical solicitations and the capability to adapt to flexible substrates are the central point for the potential ubiquitous application, implementation into PPE and the active monitoring, with minor or no maintenance, from remote locations and with embedded possibility for data transmission and emergency signal collection from remote location.

The system is furthermore interesting as it provides a substantial output signal without being perceived by the wearer: this invisible intelligence is expected to provide a fundamental basis for the technological application and the end users acceptance. According to studies and researches, the use of PPE (in any field and types of application) is sometimes lacking, due to different reasons: poor usability, hindrance of movements and limited perception of the effective protection are among the most critical aspects. Although the overall number of accidents per unit of workers in different sectors (providing more than 3 days absence from work) can not be avoided with the adoption of monitoring elements and biological parameters control, up to 15 – 20% can be imputed to loss of conscience of the worker, due to physical problems, and associated problems deriving therefrom.

The global number of incidents involving more than 3 days hospitalization and deaths, for the manufacturing European industrial sector, female and male, is:

- More than 3 Days absence 588.604 female and 2.628.409 male, in 2006 (EUROSTAT),
- Fatal Accidents 135 female and 3580 male.

It is reasonable to state that at least a 10% of such events could be avoided or the related problems limited, by an early intervention associated to the detection of the problem (can be a heat strike, sickness due to environmental conditions, heart attack or slowed cardiologic frequency due to toxins or bad air conditions, and these diseases can be detected with adequate composition – settings of the sensor system…). The monitoring of the problem when it is in its first status, that could be communicated to the wearer according to specific interfaces sound, LEDs, any other type of alert for the wearer of the problem before it is reaching a non-return point) as well transmitted to a monitoring centre, available for collecting the communication of any health related issue, enabling fast intervention and prevention of the worst danger situations for the wearer. It is clear that such ancillary products, already available on the market, are out of the scope of the project and could be integrated with the results of the project, at a minor investment from the main stakeholders already operating in the field.

The hospitalization costs for such accidents, as well as the consequent loss of work, do constitute a heavy social cost, with a wide impact, and the effects are homogeneously spread across Europe. Taking into account that an average of 5 days hospitalization is foreseen, the social costs can be estimated to be exceeding 5 billion €, averaging an overall number of 16 million working days lost, to which balance the accessory costs for rehabilitation and surgical intervention have to be added.

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