Development of a pressure sensor network system for static and dynamic pressure measurements: application to the limb/prosthesis pressure mapping

Tese de doutoramento em Ciências - FísicaThe present work relates to the development of a sensors network for mapping the pressure fields at the externa! prosthesis socket/stump interface, in particular at lower limbs. The project consists on the design and implementation of a sensor array from piezoresistive polymer based materiais to measure quasi-static and dynamic deformations. The sensors were prepared from poly(vinylidene fluoride) - PVDF and epoxy nanocomposites with carbon nanotubes or nanofibres. The development of thin film-based stretchable electrodes was carried out using the GLancing Angle Deposition, GLAD, technique. A specific electronic circuit for signal processing was used with a wireless data acquisition system. Finally, a prototype was designed , constructed and tested in four IO\.ver limb amputees, in laboratory conditions , under different types of solicitations at the Vocational Rehabilitation Center - CRPG (Centro de Reabilitação Profissional de Vila Nova de Gaia). The piezoresistive-based sensors were developed using two different approaches; a) nanocomposites composed of poly(vinylidene~ fluoride) filled with carbon nanotubes (CNT/PVDF); and b) epoxy resins filled with carbon nanotubes or nanofibres (CNT/EPOXY). The PVDF samples were prepared by hot pressing and spray printing with CNT sample concentrations up to loadings of 1 O wt.%. The phase present in the composites CNT/PVDF was the alfa-phase. Due to the fact that externa! limb prostheses must sustain cyclic loading and unloading during normal walking conditions, the correlation between the electrical resisitivity and mechanical solicitations was obtained for differents mechanical solicitations, including variations in deformation , temperature and velocity. ln relation to CNT/EPOXY, the electrical response is linear over a wide strain range and the values of the maximum gauge factor is ~2 . 8 . The stability of the signal over 32 cycles, the time response to deformatoins from 0.1 to 50 mm min- 1 and the stable temperature behaviour up to 60 °C shows the viability of these materiais to be used as piezoresistive sensors. ln the sarne way, the electrical and piezoresistive response of CNT/PVDF composites has been studied. The piezoresistive response, quantitatively analysed by the gauge factor, is maximized at concentrations around the percolation threshold, around 2 wt.% loading, and the maximum value of the gauge factor is ~6.2. The piezoresistive response is stable with the number of cycles and reversible up to temperatures below 100 °C. The linearity of the response over a wide strain range shows the viability of these materiais to be used as piezoresistive sensors. The development of stretchable electrodes was carried out using columnar Ti-Ag thin films with a Ag content of 8 at.% prepared by D.C. magnetron sputtering on CNT/PVDF piezoresistive composites. The Ti-Ag system was chosen to coat the polymers due to some important points related to its characteristics. First of ali, Ti-Ag thin films combine the excellent biocompatibility of Ti with the Ag antimicrobial properties, offering also good thermal, electrical , chemical and mechanical properties, together with good wear and corrosion resistance. Secondly, the addition of Ag was also thought in order to tailor the elasticity of the Ti films, allowing a better response of the coated polymer under any particular deformation or stretching of the composite sensor when in-service. Additionally, the deposition of the films by GLancing Angel Deposition , GLAD, instead of conventional Magnetron Sputtering Deposition , MSD, was also carried to allow and even extend this elasticity resistance. ln fact, by depositing films with some particular architectures , inclined, zigzag, etc., there is a real possibility to deposit thin films with extended capacities to resist to stretching or any common deformation that a polymeric-based sensor induce when in-service. Furthermore, there is also the possibility to improve the electrical response of the system and this, ali together, to improve the response and the adequacy of the ali sensor arrangement in this particular type of applications . By changing the typical columnar growth microstructure, obtained by conventional sputtering, the goal was to tune the mechanical and electrical responses of the materiais. Upon uniaxial stretching of the prepared zigzag thin films, the resistance of the thin film starts increasing smoothly for strains up to 3%. Above 10% strain a sharp increase of the electrical resistance is observed due to film mechanical failure and therefore interruption of the electrical conductivity pathways. The best results were obtained when the polymer was coated with intermediate incident angles (a = 60°). The results show that the electrodes structure has a pronounced influence on the overall sensor response leading to values of the GF up to 85 mainly due to the electromechanical contribution of the thin film, which stability has to be studied for potential use for sensor applications itself. Human study was conducted at the Vocational Rehabilitation Center- CRPG (Centro de Reabilitação Profissional de Vila Nova de Gaia). The subjects transfemoral (TF) and transtibial (TI) amputees , walked for 2 minutes in a crosswalk at a relatively comfortable speed of 0.33 m/s. During this time it was possible to simulate a normal walk of approximately 40 m and the results provided good indications that it is possible to identify areas of criticai pressure. Thus, it is expected that the present method will become helpful for comprehensively evaluating the biomechanical conditions of the residual limb and prosthesis interface. The system developed in this project may allow monitoring of the process of rehabilitation with a new prosthesis and will support clinical decisions in relation to the potential effects of modifications on the socket, when adjustments are required.O presente trabalho descreve o desenvolvimento de uma matriz de sensores para mapear as pressão exercidas em próteses externas dos membros inferiores, na interface coto/prótese, baseados em materiais piezoresistivos para medir as deformações dinâmicas e quasi-estáticas . Os sensores foram preparados a partir de nanocompósitos de poli(fluoreto de vinilideno) - PVDF e resinas epoxy com nanotubos- CNT ou nanofibras- CNF de carbono. Adicionalmente, foram desenvolvidos elétrodos estiráveis baseados em filmes finos através da técnica de pulverização catódica GLAD, Glancing Angle Deposition. O circuito electrónico usado para o processamento de sinal foi desenvolvido com um sistema de aquisição de dados sem fios. Finalmente, foi construído um protótipo que foi testado em quatro pacientes amputados dos membros inferiores em condições de laboratório, sob diferentes tipos de solicitações no centro de reabilitação vocacional - CRPG (Centro de Reabilitação Profissional de Vila Nova de Gaia). Com base no efeito piezoresistivo , os sensores foram obtidos usando duas diferentes ... abordagens; a) compósitos de poli(fluoreto de vinilideno) com nanotubos de carbono (CNT/PVDF); e b) compósitos de resinas epóxi com nanotubos de carbono ou nanofibras (CNT/epóxi). As amostras de PVDF foram preparadas por prensagem a quente e/ou por spray com concentrações de CNT até 10 % em peso. A fase cristalina presente nos compósitos CNT/PVDF foi a fase alfa-PVDF. Foi obtida a correlação entre a resistividade elétrica e as diferentes solicitações mecânicas, através da deformação , da variação da temperatura, da velocidade e do tempo de resposta do compósito. Em relação aos compósitos de CNT/epóxi, obteve-se uma resposta elétrica linear e os valores de sensibilidade máxima (gauge factor) foram de ~ 2.8. Através das diferentes solicitações mecânicas , a estabilidade do sinal para mais de 32 ciclos, o tempo de resposta para deformações de 0.1 a 50 mm min· 1 e a estabilidade com a temperatura até 60 oc mostram a viabilidade destes materiais para serem utilizados como sensores piezoresistivos. Da mesma forma , a resposta elétrica e piezoresistiva dos compósitos de CNT/PVDF foi estudada. A resposta piezoresisitiva foi quantitativamente analisada pela sensibilidade do material (gauge factor) e verificou-se que é máxima para concentrações em tomo do limiar de percolação, ~2 % de CNT em peso, e o valor máximo obtido foi de ~ 6.2. A resposta piezoresistiva é estável em função do número de ciclos e reversível até temperaturas inferiores a 100 °C. A linearidade da resposta com a deformação mostra a viabilidade destes materiais para serem utilizados como sensores piezoresistivos. O desenvolvimento de elétrodos estiráveis foi realizado usando filmes finos com estrutura colunar de titânio e prata - Ti-Ag com um teor de Ag de 8 at.% preparados por pulverização catódica em compósitos piezoresistivos de CNT/PVDF. O sistema Ti-Ag foi escolhido para revestir os polímeros devido a alguns pontos importantes relacionados com as suas características. Primeiro de tudo , filmes finos de Ti-Ag combinam a excelente biocompatibilidade do titânio com as propriedades anti-microbianas da prata, oferecendo deste modo boas propriedades químicas, mecânicas e elétricas, juntamente com boas propriedades de resistência ao desgaste e corrosão. Segundo, a adição de prata também foi incluída com o objetivo de promover a elasticidade do filme de modo a permitir uma melhor adaptação do filme ao polímero. Por outro lado, o sistema GLAD teve por grande objetivo este mesmo propósito: melhorar a resposta elétrica e a elasticidade do sistema de modo a permitir uma melhor adequação à deposição dos elétrodos em materiais flexíveis. A técnica de GLAD foi usada para alterar a microestrutura típica de crescimento colunar obtida por pulverização catódica convencional , Magnetron Sputtering Deposition, MSD, em diferentes arquiteturas de crescimento , tais como colunas inclinadas e em ziguezague, a fim de ajustar as respostas meéânicas e elétricas dos materiais. Após estiramento uniaxial dos filmes finos em ziguezague, a resistência eléctrica do filme fino começa a aumentar tenuemente para tensões até 3%. Acima de 10% de estiramento dá-se um aumento acentuado da resistência eléctrica que é observado devido à falha mecânica do filme . Os melhores resultados foram obtidos quando o polímero foi revestido com filmes depositados com ângulos incidentes intermédios (a = 60 °). Os resultados mostram que a estrutura dos elétrodos tem uma acentuada influência sobre a resposta global do sensor levando a valores de sensibilidade até 85. Esta contribuição deve-se essencialmente à contribuição eletromecânica do filme fino. O estudo com Pacientes foi realizado no centro de reabilitação profissional- CRPG (Centro de Reabilitação Profissional de Gaia), com amputados transfemoral (TF) e amputados transtibial (TT), que caminharam durante 2 minutos numa passadeira eléctrica com uma velocidade relativamente confortável de 0,33 rn/s. Durante este tempo , foi possível simular uma marcha normal de aproximadamente 40m. Deste modo demonstrou-se que é possível identificar as áreas criticas de pressão. Espera-se que, o presente método, se tome útil para avaliar exaustivamente as interações biomecânicas entre o membro amputado e a prótese. O sistema desenvolvido neste projeto poderá permitir o monitoramento durante o processo de reabilitação e apoiar em decisões clínicas em relação aos potenciais efeitos e modificações do encaixe da prótese no coto .Fundação para a Ciência e a Tecnologia (FCT) for the financial support (SFRH/BD/69796/2010)

Estudo da influência da micro/nanoestrutura superficial na adesão de filmes finos de TiNx em materiais de Tereftalato de Polietileno (PET)

Dissertação de mestrado (área de especialização Física de Materiais Avançados)Materiais poliméricos têm uma vasta gama de aplicações devido às suas características, tais como serem leves, flexíveis e, em geral, terem baixo custo. Contudo, para determinadas aplicações, é necessária a funcionalização da superfície, por exemplo, por recurso ao revestimento por um filme fino. No entanto, os problemas de adesão dos filmes finos à grande maioria dos materiais poliméricos são bem conhecidos. A literatura revela que tratamentos de superfície nos polímeros melhoraram a sua adesão aos filmes finos, aumentando o leque de possíveis aplicações. Entre os vários tratamentos conhecidos está o tratamento por plasma. Neste trabalho, foram realizados tratamentos de superfícies de vários tipos de polímeros (polietileno tereftalato, policarbonato, poli(fluoreto de vinilideno), utilizando para o efeito um plasma, criado num equipamento de pulverização catódica reactiva em magnetrão (alimentação DC). Foi realizada ainda a avaliação das modificações a nível da superfície do polímero – polietileno tereftalato (PET) –, através das técnicas de microscopia de força atómica e ângulos de contacto. Verificou-se que um aumento do ângulo de contacto está relacionado com um aumento da rugosidade média. Obtiveram-se valores de ângulo de contacto variando entre 71 – 84º, para variações de rugosidade média entre 3,3 e 7,2 nm, em função dos diferentes tratamentos de superfície. Por Espectroscopia de Infravermelho por Transformada de Fourier em modo de reflexão total atenuada não se verificaram alterações químicas significativas no material. Por difracção de raios-X não foram detectáveis alterações, quer na posição angular dos picos de difracção do polímero, quer da própria intensidade. As propriedades mecânicas dos substratos não se alteraram, independentemente do tratamento da superfície. As curvas de tensão – deformação mostraram-se similares ao material sem tratamento: lineares até cerca de 8% da deformação, seguida por uma deformação plástica. O módulo de Young, tensão de cedência e ruptura do PET sem tratamento são: 2.1 GPa, 109.4 MPa e 153.3 MPa, respectivamente. Dentro do erro experimental, estes valores não se alteraram para os diferentes tratamentos. A aderência do filme de nitreto de titânio (TiN) ao polímero é muito forte, não houve uma remoção clara do filme, independente do método de teste, norma ASTM – D3359 – 97 ou teste peeling a 90º. Os resultados obtidos foram aplicados na construção de um teclado piezoeléctrico flexível.Polymeric materials have a wide range of applications due to its characteristics, such as being lightweight, flexible, and generally have low cost. However, for certain applications, it is necessary to surface functionalization, for example, by use of coating a thin film. However, the problems of adhesion of thin films to the great majority of polymeric materials are well known. The literature shows that surface treatments in polymers improved their adherence to the thin films, increasing the range of possible applications. Among the various treatments known is the plasma treatment. This work was carried out surface treatments of various types of polymers (polyethylene terephthalate, polycarbonate, poly(vinylidene fluoride), using a plasma effect, created in the equipment for reactive sputtering in magnetron (DC power). Was further the evaluation of modifications to the surface of the polymer - polyethylene terephthalate (PET) -, through the techniques of atomic force microscopy and contact angles. It was found that an increase in contact angle is related to an increase in the average roughness, obtained values of contact angle ranging from 71 to 84º thereof, to changes in average roughness between 3.3 and 7.2 nm for different surface treatments. By Fourier Transform Infrared Spectroscopy in mode of attenuated total reflection there were no significant chemical changes in the material. By X-ray diffraction were not detectable changes in the angle of diffraction peaks of the polymer, or in the intensity. The mechanical properties of the substrates did not change regardless of treatment surface. The curves of stress - strain are similar to the material without treatment: linear up to about 8% of strain, followed by a plastic deformation. The Young modulus, yielding stress and strain of the materials stay, within experimental error, within the values obtained for the untreated polymer: 2.1 GPa, 109.4 MPa and 153.3 MPa, respectively. The adhesion of the film of titanium nitride (TiN) to the polymer is very strong, there wasn’t a clear removal of the film, independent the test method, ASTM - D3359 - 97 or peeling test at 90 °. The results were applied in the construction of a piezoelectric flexible keyboard

Structural, mechanical, and decorative properties of sputtered TiN and Ti (N, C) films for orthodontic applications; an in vitro study

In this paper, we explore and modify the structural, mechanical, and decorative properties of films composed by TiN and Ti (N, C) with a wide range of N2 gas flow during the deposition in order to be used on orthodontic systems. The films were grown using reactive DC magnetron sputtering from a pure Ti target and customized with C pellets onto Si and stainless steel 316L substrates. The structural properties were studied using X-ray diffraction and scanning electron microscopy, while the mechanical ones were obtained through hardness, elastic modulus, and friction coefficient. Moreover, the wear rate has been measured under an artificial saliva medium to simulate the oral cavity. The color of the films deposited onto stainless steel 316 L substrate was characterized through CIELab color code. Our findings show that the addition of N2 and C in the Ti matrix improves the mechanical properties of the films. With the increase in the amount of N2 and C, the hardness reaches a value of 739 HV, higher than the one reported in the literature (600 HV), a low value of the coefficient of elasticity (8.0 GPa), and also a low friction coefficient (0.30). Moreover, with the addition of N2 and C in the Ti films, the color of the films changes from metallic aspect until “with” gold, which means that our coatings exhibit versatile mechanical and color characteristics to be used in orthodontic wires applications.FCT -Fundação para a Ciência e a Tecnologia(PIBA-2018-06

Piezoresistive response of nano-architectured TixCuy thin films for sensor applications

The present work reports on the development of piezoresistive TixCuy thin films, deposited on polymeric substrates (PET). The general idea was to analyse the influence of the Cu concentration on the signal response of the Ti-based transducers, exploring the possibility to use this thin film system as force and deformation sensors in biomedical sensing devices. The GLancing Angle Deposition, GLAD, technique was used to change the typical normal columnar growth microstructure into inclined (zigzag-like) architectures, aiming to tune the mechanical and electrical responses of the thin films, which may offer unique opportunities for several sensing devices. Inclined (zigzag grown) thin films were prepared with increasing amounts of Cu and characterized in terms of the most relevant properties for sensing applications. The piezoresistive response was analyzed trough the evaluation of the Gauge Factor, K. The incident angles of the particle flux = 45º were used to prepare the nano-architectured zigzag TixCuy thin films. The Gauge factor ranges from 1.24 ± 0.03 to 16.34±0.43 for intermetallic Ti0.92Cu0.08 and pure Cu thin films, respectively. For the deposited thin films small voids are formed and the voids density decreases considerably with increasing Cu content. Taking in account the: electrical resistance linearity, low noise and the highest K value found for TixCuy films (K= 3.6±0.1), the most promising results were obtained when the polymer was coated with a stoichiometry ofTi0.37Cu0.63. The overall set of results also show the viability of these materials to be used as piezoresistive sensors, namely in biological environments, such as catheters, needles or endoscopes with sensing capabilities.The authors also thank FCT for financial support: A. Ferreira and C. Lopes thanks the FCT for grant SFRH/BPD/102402/2014 and SFRH/BD/103373/2014. The authors thank financial support from the Basque Government Industry Department under the ELKARTEK Program. SLM thanks the Diputación de Bizkaia for financial support under the Bizkaia Talent program

Poly(vinylidene fluoride-trifluoroethylene) (72/28) interconnected porous membranes obtained by crystallization from solution

Electroactive macroporous poly[(vinylidene fluoride)-co-trifluoroethylene] mambranes membranes have been processed by solvent evaporation at room temperature with different polymer/solvent concentrations. The pore architecture consists of on an interconnected spherical pores and this morphology is independent of the membrane thickness. The porosity of the produced membranes increases from 57% for the higher polymer concentration in the polymer/solvent solution (15/85), up to 83% for the lowest polymer amount in the polymer/solvent solution. Far infrared and differential scanning calorimetry measurements reveal that the polymer crystallizes in the ferroelectric phase and the polymer/solvent ratio does n’t not changes the Curie transition and the melting temperature of the polymer.The authors thank the Portuguese FCT (Grants PTDC/CTM/73030/2006, PTDC/CTM/69316/2006 and NANO/NMed-SD/0156/2007 and SFRH/BPD/63148/2009 (V.S.)) and the Spanish Ministry of Education and Ministry of Science and Innovation (Project No. MAT2007-66759-C03-01)

Directional field-dependence of magnetoimpedance effect on integrated YIG/Pt-stripline system

We investigated the magnetization dynamics through the magnetoimpedance effect in an integrated YIG/Pt-stripline system in the frequency range of 0.5 up to 2.0 GHz. Specifically, we explore the dependence of the dynamic magnetic behavior on the field orientation by analyzing beyond the traditional longitudinal magnetoimpedance effect of the transverse and perpendicular setups. We disclose here the strong dependence of the effective damping parameter on the field orientation, as well as verification of the very-low damping parameter values for the longitudinal and transverse configurations. We find considerable sensitivity results, bringing to light the facilities to integrate ferrimagnetic insulators in current and future technological applications.This research was funded by CNPq grand numbers 304943/2020-7 and 407385/2018-5, Capes grand number 88887.573100/2020-00 and FCT grant number CTTI-31/18-CF(2)

High performance of metallic thin films for resistance temperature devices with antimicrobial properties

Titanium-copper alloy films with stoichiometry given by Ti1−xCux were produced by magnetron co-sputtering technique and analyzed in order to explore the suitability of the films to be applied as resistive temperature sensors with antimicrobial properties. For that, the copper (Cu) amount in the films was varied by applying different DC currents to the source during the deposition in order to change the Cu concentration. As a result, the samples showed excellent thermoresistivity linearity and stability for temperatures in the range between room temperature to 110 °C. The sample concentration of Ti0.70Cu0.30 has better characteristics to act as RTD, especially the αTCR of 1990 ×10−6°C−1. The antimicrobial properties of the Ti1−xCux films were analyzed by exposing the films to the bacterias S. aureus and E. coli, and comparing them with bare Ti and Cu films that underwent the same protocol. The Ti1−xCux thin films showed bactericidal effects, by log10 reduction for both bacteria, irrespective of the Cu concentrations. As a test of concept, the selected sample was subjected to 160 h reacting to variations in ambient temperature, presenting results similar to a commercial temperature sensor. Therefore, these Ti1−xCux thin films become excellent antimicrobial candidates to act as temperature sensors in advanced coating systems.This work was supported by FCT-UIDB/04650/2020. A.L.R.S. thanks CAPES (88887.572905 /2020-00) and CNPq. M.A.C. thanks CAPES (8887.573100/2020-00) and CNPq. A.F. thanks the FCT (CTTI-31/18-C.F. (2) junior researcher contract)

Anomalous Nernst Effect in flexible co-based amorphous ribbons

Fe3Co67Cr3Si15B12 ribbons with a high degree of flexibility and excellent corrosion stability were produced by rapid quenching technique. Their structural, magnetic, and thermomagnetic (Anomalous Nernst Effect) properties were studied both in an as-quenched (NR) state and after stress annealing during 1 h at the temperature of 350 °C and a specific load of 230 MPa (AR). X-ray diffraction was used to verify the structural characteristics of our ribbons. Static magnetic properties were explored by inductive technique and vibrating sample magnetometry. The thermomagnetic curves investigated through the Anomalous Nernst Effect are consistent with the obtained magnetization results, presenting a linear response in the thermomagnetic signal, an interesting feature for sensor applications. Additionally, Anomalous Nernst Effect coefficient SANE values of 2.66μV/K and 1.93μV/K were estimated for the as-quenched and annealed ribbons, respectively. The interplay of the low magnetostrictive properties, soft magnetic behavior, linearity of the thermomagnetic response, and flexibility of these ribbons place them as promising systems to probe curved surfaces and propose multifunctional devices, including magnetic field-specialized sensors.M.A.C. thanks CAPES (8887.573100/2020-00) and CNPq. A.F. thanks the FCT (CTTI-31/18- C.F. (2) junior researcher contract). G.V.K was supported in the frame of the Priority-2030 Program of Ural Federal University

Improving the room-temperature ferromagnetism in ZnO and low-doped ZnO:Ag films using GLAD sputtering

ZnO and doped ZnO films with non-ferromagnetic metal have been widely used as biosensor elements. In these studies, the electrochemical measurements are explored, though the electrical impedance of the system. In this sense, the ferromagnetic properties of the material can be used for multifunctionalization of the sensor element using external magnetic fields during the measurements. Within this context, we investigate the room-temperature ferromagnetism in pure ZnO and Ag-doped ZnO films presenting zigzag-like columnar geometry. Specifically, we focus on the films’ structural and quasi-static magnetic properties and disclose that they evolve with the doping of low-Ag concentrations and the columnar geometry employed during the deposition. The magnetic characterization reveals ferromagnetic behavior at room temperature for all studied samples, including the pure ZnO one. By considering computational simulations, we address the origin of ferromagnetism in ZnO and Ag-doped ZnO and interpret our results in terms of the Zn vacancy dynamics, its substitution by an Ag atom in the site, and the influence of the columnar geometry on the magnetic properties of the films. Our findings bring to light an exciting way to induce/explore the room-temperature ferromagnetism of a non-ferromagnetic metal-doped semiconductor as a promising candidate for biosensor applications.This works was partially supported by the Brazilian agencies CNPq and CAPES. Furthermore, this work was also supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2019 and project PTDC/BTMMAT/28237/2017. A. Ferreira thanks FCT for the contract under the Stimulus of Scientific Employment (CTTI-31/18–CF (2) junior researcher contract). RMT thanks the Center for Computational Engineering & Sciences (CCES) at Unicamp for financial support through the FAPESP/CEPID Grant 2013/08293-7. LDM would also like to thank the support of the High-Performance Computing Center at UFRN (NPAD/UFRN). The work reported in this paper was supported by On-Surf Mobilizar Competencias Tecnologicas em Engenharia de Superficies, Project POCI-01-0247-FEDER-024521

Longitudinal Spin Seebeck Effect thermopiles based on flexible Co-rich amorphous ribbons/Pt thin-film heterostructures

Thermoelectric phenomena, such as the Anomalous Nernst and Longitudinal Spin Seebeck Effects, are promising for sensor applications in the area of renewable energy. In the case of flexible electronic materials, the request is even larger because they can be integrated into devices having complex shape surfaces. Here, we reveal that Pt promotes an enhancement of the thermoelectric response in Co-rich ribbon/Pt heterostructures due to the spin-to-charge conversion. Moreover, we demonstrated that the employment of the thermopiles configuration in this system increases the induced thermoelectric current, a fact related to the considerable decrease in the electric resistance of the system. By comparing present findings with the literature, we were able to design a flexible thermopile based on LSSE without the lithography process. Additionally, the thermoelectric voltage found in the studied flexible heterostructures is comparable to the ones verified for rigid systems.This research was funded by different sources. M.A.C. thanks CAPES (8887.573100/2020-00) and CNPq. A.F. thanks the FCT (CTTI-31/18-C.F. (2) junior researcher contract). A.V.S. and G.V.K. were supported in the frame of the Priority-2030 Program of Ural Federal University