Adhesion Of Films Research Articles

Biomechanics of a Plant-Derived Sealant for Corneal Injuries.

The corneal epithelium has a glycocalyx composed of membrane-associated glycoproteins, mucins, and galactin-3. Similar to the glycocalyx in visceral tissues, the corneal glycocalyx functions to limit fluid loss and minimize frictional forces. Recently, the plant-derived heteropolysaccharide pectin has been shown to physically entangle with the visceral organ glycocalyx. The ability of pectin to entangle with the corneal epithelium is unknown. To explore the potential role of pectin as a corneal bioadhesive, we assessed the adhesive characteristics of pectin films in a bovine globe model. Pectin film was flexible, translucent, and low profile (80 µm thick). Molded in tape form, pectin films were significantly more adherent to the bovine cornea than control biopolymers of nanocellulose fibers, sodium hyaluronate, and carboxymethyl cellulose (P < 0.05). Adhesion strength was near maximal within seconds of contact. Compatible with wound closure under tension, the relative adhesion strength was greatest at a peel angle less than 45 degrees. The corneal incisions sealed with pectin film were resistant to anterior chamber pressure fluctuations ranging from negative 51.3 ± 8.9 mm Hg to positive 214 ± 68.6 mm Hg. Consistent with these findings, scanning electron microscopy demonstrated a low-profile film densely adherent to the bovine cornea. Finally, the adhesion of the pectin films facilitated the en face harvest of the corneal epithelium without physical dissection or enzymatic digestion. We conclude that pectin films strongly adhere to the corneal glycocalyx. The plant-derived pectin biopolymer provides potential utility for corneal wound healing as well as targeted drug delivery.

Facile Implementation of Antimicrobial Coatings through Adhesive Films (Wraps) Demonstrated with Cuprous Oxide Coatings.

Antimicrobial coatings have a finite lifetime because of wear, depletion of the active ingredient, or surface contamination that produces a barrier between the pathogen and the active ingredient. The limited lifetime means that facile replacement is important. Here, we describe a generic method for rapidly applying and reapplying antimicrobial coatings to common-touch surfaces. The method is to deposit an antimicrobial coating on a generic adhesive film (wrap), and then to attach that modified wrap to the common-touch surface. In this scenario, the adhesion of the wrap and antimicrobial efficacy are separated and can be optimized independently. We demonstrate the fabrication of two antimicrobial wraps, both using cuprous oxide (Cu2O) as the active ingredient. The first uses polyurethane (PU) as the polymeric binder and the second uses polydopamine (PDA). Our antimicrobial PU/Cu2O and PDA/Cu2O wraps, respectively, kill >99.98% and >99.82% of the human pathogen, P. aeruginosa, in only 10 min, and each of them kill >99.99% of the bacterium in 20 min. These antimicrobial wraps can be removed and replaced on the same object in <1 min with no tools. Wraps are already frequently used by consumers to coat drawers or cars for aesthetic or protective purposes.

An Efficient Procedure for Bonding Piezoelectric Transducers to Thermoplastic Composite Structures for SHM Application and Its Durability in Aeronautical Environmental Conditions

Piezoceramic transducers (PCTs) bonded to carbon fiber-reinforced plastic (CFRP) composite structures must be durable as well as remain properly bonded to the structure in order to provide reliable data for accurate guided-wave-based structural health monitoring (SHM) of aeronautical components. The current method of bonding transducers to composite structures through epoxy adhesives faces some shortcomings, such as difficult reparability, lack of weldability, longer curing cycles, and shorter shelf life. To overcome these shortcomings, a new efficient procedure for bonding the transducers to thermoplastic (TP) composite structures was developed by utilizing TP adhesive films. Application-suitable TP films (TPFs) were identified and characterized through standard differential scanning calorimetry (DSC) and single lap shear (SLS) tests to study their melting behavior and bonding strength, respectively. Special PCTs called acousto-ultrasonic composite transducers (AUCTs) were bonded to high-performance TP composites (carbon fiber Poly-Ether-Ether-Ketone) coupons with a reference adhesive (Loctite EA 9695) and the selected TPFs. The integrity and durability of the bonded AUCTs in aeronautical operational environmental conditions (AOEC) were assessed in accordance to the standard Radio Technical Commission for Aeronautics DO-160. The AOEC tests performed were operating low and high temperatures, thermal cycling, hot-wet, and fluid susceptibility tests. The health and bonding quality of the AUCTs were evaluated by the electro-mechanical impedance (EMI) spectroscopy method and ultrasonic inspections. The AUCT defects were created artificially and their influence on the susceptance spectra (SS) was measured to compare them with the AOEC-tested AUCTs. The results show that a small change occurred in the SS characteristics of the bonded AUCTs in all of the adhesive cases after the AOEC tests. After comparing the changes in SS characteristics of simulated defects with that of the AOEC-tested AUCTs, the change is relatively smaller and therefore it can be concluded that no serious degradation of the AUCT or the adhesive layer has occurred. It was observed that the most critical tests among the AOEC tests are the fluid susceptibility tests, which can cause the biggest change in the SS characteristics. Comparing the performance of the AUCTs bonded with the reference adhesive and the selected TPFs in the AOEC tests, it was seen that some of the TPFs, e.g., Pontacol 22.100 outperforms the reference adhesive, while the other TPFs have similar performance to that of the reference adhesive. Therefore, in conclusion, the AUCTs bonded with the selected TPFs can withstand the operational and environmental conditions of an aircraft structure, and hence, the proposed procedure is easily installed, reparable, and a more reliable method of bonding sensors to aircraft structures.

B-doped nanodiamond composite hard coatings deposited on cemented carbide: Mechanical, structural, and tribological properties

Herein, the effects of B doping on the mechanical, structural, and tribological properties of nanodiamond composite (NDC) coatings deposited on cemented tungsten carbide-based Co binder substrates via coaxial arc plasma deposition are studied. The results reveal decreasing films hardness 35, 27, and 25 GPa with increasing B contents of 1, 5, and 10 at.%, respectively, which is attributed to film graphitisation. Graphitisation is induced by the catalytic effects of Co atoms, which diffuse proportionally from the substrate surface into the films with increasing B content. However, Co diffusion hardly occurs during the deposition of undoped films. The 1 at.% B-doped films with an undoped NDC buffer layer exhibit enhanced hardness from 35 to 58.3 GPa owing to a decrease in the catalytic effects of Co, thereby resulting in the formation of a high amount of CC sp3 bonds at the expense of CC sp2 bonds. The adhesion of the doped films is improved by a factor of three compared with the undoped films owing to enhanced film hardness and toughness as B doping tends to release internal stress by forming long CB bonds. The sliding behaviour remains at a friction coefficient of approximately 0.08 owing to the presence of sacrificial B2O sliding layers and graphitic self-lubrication phases. The B-doped NDC films are promising hard coatings for machining difficult-to-cut materials.

Tailoring the Wettability and Substrate Adherence of Thin Polymer Films with Surface-Segregating Bottlebrush Copolymer Additives.

We developed "reactive" bottlebrush polymers based on styrene (S) and t-butyl acrylate (tBA) as additives for polystyrene (PS) coatings. The bottlebrush polymers spontaneously bloom to both the air and substrate interfaces during solution casting. While neat PS films are hydrophobic and poorly adhere to the native oxide on clean silicon wafers, the hydrophilicity and substrate adherence of bottlebrush-incorporating PS films can be tailored through the thermally activated deprotection of tBA to produce acrylic acid (AA) and acrylic anhydride (AH). A critical design parameter is the manner by which tBA is incorporated into the bottlebrush: When the bottlebrush side chains are copolymers of S and tBA, the extent of deprotection is extremely low, even after prolonged thermal annealing at elevated temperature. However, when the bottlebrush contains a mixture of poly(t-butyl acrylate) (PtBA) and PS side chains, nearly all tBA is converted to AA and AH. Consequently, using the "mixed-chain" bottlebrush design with thermal processing and appropriate conditioning, the water contact angle is reduced from over 90° on unmodified PS down to 75° on bottlebrush-incorporating PS films, and the substrate adherence is improved in proportion to the extent of tBA deprotection.

Fabrication and Application of Eco-friendly Bamboo Self-Bonded Composites for Furniture

Self-bonding technology is a facile and green molding approach to obtain eco-friendly and formaldehyde-free bamboo self-bonded composites (BSCs), yet the manufacture process is still immature. Here, the effects of processing parameters (moisture content of bamboo powders, hot-pressing temperature, and preset density) were comprehensively examined on the microstructure, physical properties, and mechanical properties of the BSCs for use in furniture. It was found that the optimum water resistance and mechanical properties were achieved for the BSCs made of bamboo powders of 40% moisture content. Higher temperature and preset density facilitated the formation of a more compact structure, leading to remarkable improvement in water resistance and mechanical performance. Given energy saving, the recommended processing parameters of the BSC manufacture were 40% moisture content of bamboo powders, 200 °C hot-pressing temperature, and 1.0 g/cm3 preset density, yielding high-performance BSCs with a thickness swelling of 12.8% and internal bonding strength of 0.71 MPa, which were comparable to commercial furniture-grade medium-density fiberboards. The colorful patterns could be successfully printed by a UV inkjet printer on the BSC surface and exhibited good paint film adhesion, which holds great potential for application in furniture.

Enhancement of the electrical and thermal conductivity of epoxy-based composite films through the construction of the multi-scale conductive bridge structure

Electrically conductive adhesive films (ECAFs), a novel electrically and thermally adhesive material, have been widely used in the large-area bonding of microelectronics packaging. However, it is still a challenge to optimize the silver micro-flakes (Ag-MFs) dispersion, and build a more effective electrically and thermally conductive network. In this study, we improved the dispersion of Ag-MFs in epoxy matrix through the intermolecular hydrogen bonding, and proposed a new multi-scale conductive bridge structure. Specifically, poly (3,4-ethylenedioxythiophene)/poly (styrene sulfonate) (PEDOT/PSS or P/P for short) can form the intermolecular hydrogen bonding with Ag-MFs based on the sulfonic groups of PSS chain and the carboxyl group located on the surface of Ag-MFs, resulting in improving dispersion of Ag-MFs. Besides, PEDOT can occur conformation change from benzoid conformation to quinone conformation and form PEDOT conductive crystalline nanofibril, and then multi-scale conductive bridge structure with Ag-MFs were constructed. Moreover, the initial viscosity of epoxy-based composite is maintained within 106 mPa s, which means Ag-MFs is uniformly dispersed after the addition of P/P. Scanning electron microscopy (SEM) and oscillating viscoelastic measurement were used to demonstrate the improved dispersion of Ag-MFs after the addition of P/P. In addition, atomic force microscope (AFM) and Raman spectroscopy were used to verify the conformation change of PEDOT. Compared with ECAF without P/P, the electrical and thermal conductivity of ECAF with 6 wt% P/P was enhanced by 73.1% and 166.3%, respectively. Meanwhile, scattering parameter (S-parameter) measurements demonstrated that ECAF with 6 wt% P/P had excellent radio-frequency behavior at 2–4 GHz, indicating high-performance in the microelectronics packaging industry.

Study on Preparation and Performance of Polyurethane Hot Melt Adhesive Films

Polyurethane hot melt adhesive films (PHMAFs) are green adhesives without any solvent. In this study, a series of polyurethane hot melt adhesive films with different crosslinking agent content were successfully synthesized. The melting temperature, water absorption, mechanical properties, and adhesion properties were studied. The results illustrate that the introduction of crosslinking agent could endow PHMAFs with better final adhesion strengths and water resistance ability, but also lead to decrease of tensile stress at break and elongation at break. The final T-peel strength of the films was in the range of 76.54-114.53 N/cm, which could meet the requirements of the industrial gluing in footwear.

High entropy alloy thin films on SS304 substrates: Evolution of microstructure and interface modulated by energetic condensation in nanoscale

High entropy alloys (HEAs), as a novel material in the 21st century, possess several advantages, such as excellent corrosion & oxidation resistance and high mechanical properties. HEA thin films show these favourable properties with lower material costs than their bulk counterparts. Studying the HEA film-substrate interface represents challenges but is of extreme importance for the understanding of growth mechanisms with important implications for film adhesion. However, most HEA films were deposited on monocrystalline silicon substrates with limited practical applicability. Further, where commercial stainless steel, aluminium or titanium alloy substrates were used, the microstructure and chemistry at the interface were neglected. Here, we deposited AlCrFeCoNiCu0.5 HEA thin films on stainless steel 304 (SS304) substrates using cathodic arc deposition with different substrate biases. The crystallography and microstructure were investigated using an X-ray and electron-microscopy based chatacterization. A transition of an incoherent to semi-coherent interface was observed from 0 V to -50 V of the substrate bias. Energy dispersive spectroscopy demonstrated a transition of Cr2O3 to aluminum oxide across the interface. The nanoindentation tests revealed the significant improvement of mechanical properties of SS304 with HEA coatings. High-strength HEA (8.0 ± 0.2 GPa) thin films with semi-coherent interfaces were manufactured on SS304.

Thermoplastic-based microfluidic chip bonding with PES hot melt adhesive film

ABSTRACT In this study, a low-cost and rapid bonding method for thermoplastic-based microfluidic devices is introduced. The thermoplastic substrate and cover plate were directly bonded with PES copolyester hot melt adhesive film. Compared with conventional bonding methods for thermoplastic chips, e.g. thermal fusion and chemical-assisted bonding, the proposed bonding process can be finished within minutes without sophisticated instruments or volatile chemical solvents. Several microfluidic devices were also fabricated and tested, the measured bonding strength is comparable to the conventional thermal fusion bonding method. The biocompatibility of the proposed bonding method was also evaluated by culturing bacteria in the PES adhesive covered culture dish. The proposed bonding method for thermoplastic-based microfluidic is especially suitable for the massive fabrication of POCT devices with advantages in processing speed, instrument requirement, cost, and bonding strength.

Preparation of UV Curable Optical Adhesive NOA81 Bionic Lotus Leaf Structure Films by Nanoimprint Technique and the Applications on Silicon Solar Cells

Front surface texturing is a common method used to improve the optical performance of photovoltaic devices. However, traditional texturing techniques may be challenging in some cases, such as when dealing with ultra-thin substrates. Textured polymer films on such devices would be an alternative approach. This paper reports a study of NOA81 thin films with a bionic lotus leaf surface structure on monocrystalline silicon solar cells. Inspired by the surface structure of natural lotus leaves, we successfully prepared a bionic lotus leaf microstructure film on the surface of solar cells based on NOA81 using polydimethylsiloxane (PDMS) polymer and nanoimprinting methods. Scanning electron microscopy (SEM) images showed that the surface structure of the NOA81 thin film was the same as that of natural lotus leaves. A UV-Vis spectrophotometer with an integrating sphere was used to measure the reflectance of the textured NOA81 film on the silicon wafer. Results showed that the textured NOA81 film could effectively reduce the reflectance of the silicon wafer surface. We also used finite-difference time-domain (FDTD) simulation to verify this conclusion further. Finally, the I-V characteristics of the prepared solar cells with the textured NOA81 film were investigated, and the highest photovoltaic efficiency was measured to be about 16.07%, effectively improving the photoelectric conversion efficiency. In addition, the film with textured NOA81 can be used as a protective film for monocrystalline silicon solar cells.

Evaluation of XD 10 Polyamide Electrospun Nanofibers to Improve Mode I Fracture Toughness for Epoxy Adhesive Film Bonded Joints

The demand for ever-lighter structures raises the interest in bonding as a joining method, especially for materials that are difficult to join with traditional welding and bolting techniques. Structural adhesives, however, are susceptible to defects, but can be toughened in several ways: by changing their chemical composition or by adding fillers, even of nanometric size. Nanomaterials have a high surface area and limited structural defects, which can enhance the mechanical properties of adhesives depending on their nature, quantity, size, and interfacial adhesion. This work analyzes the Mode I fracture toughness of joints bonded with METLBOND® 1515-4M epoxy film and XantuLayr electrospun XD 10 polyamide nanofibers. Two joint configurations were studied, which differed according to the position of the nanomat within the adhesive layer: one had the nanofibers at the substrate/adhesive interfaces, and the other had the nanofibers in the center of the adhesive layer. Double cantilever beam joints were manufactured to evaluate the Mode I fracture toughness of the bonding with and without nano-reinforcement. The nanofibers applied at the substrate/adhesive interface improved the Mode-I fracture toughness by 32%, reaching the value of 0.55 N/mm. SEM images confirm the positive contribution of the nanofibers, which appear stretched and pulled out from the matrix. No fracture toughness variation was detected in the joints with the nanofibers placed in the middle of the adhesive layer.

Electrically Insulative Film Adhesive with Enhanced Thermal Performance to Assemble High Power Density Electronic Devices

Assembly adhesives play a critical role in microelectronic packaging and contribute significant value for circuit assembly interconnection, protection, and thermal management. Of particular interest with today’s more powerful systems is thermal management of high-power density electronic systems, including power modules, power amplifiers, communication systems, and directed energy systems. As requirements for performance and functionality increase, heat generated from these devices increases exponentially. For example, local heat flux can easily exceed 50 W/cm2 for IGBT power modules while it may reach several hundred Watts/cm2 at active areas for Gallium Nitride (GaN) power amplifiers. Simultaneously, many of these systems demand a higher level of electrical insulation to eliminate or minimize current leakage to ensure high reliability over a long service life. Effectively and safely dissipating the high heat and ensuring excellent electrical insulation has become an increasingly critical and challenging task in the microelectronics packaging technology for aerospace and defense systems. This paper presents integration of thermally conductive adhesives with an electrically insulative polyimide film into a carefully engineered laminate, which enables high thermal transfer and robust electrical insulation. This new film adhesive provides outstanding compliance and augmented tolerance to large topographical features and warpage (5-7 mils). This film adhesive is one of the potential solutions to addresses the evolving needs of the electronics assembly industry in the areas of management of high-power systems

A study of the impact of high-speed sealing parameter gradients on the seal strength in a multilayer polypropylene film

Multilayer polymer films continue to be used in food packaging high-speed lines; this research focuses on obtaining better film adhesion under controlled sealing conditions. The present work aims to describe the presence of temperature gradients in the body of the sealing jaw, the dwell time gradients, and the surface pressure gradients, experimenting with a high-speed sealing process. The samples’ adhesion was measured using the peeling test, and the peeling graphs of the tests were analyzed to observe the differences and similarities of each sealing parameter combination. Experimental data were used to generate the surface response families of the seal strength of multilayer polymer film. The model describes, in a 3D space, the influence zones that sealing parameter gradients had on the seal strength. The surface model and experimental data indicate that temperature is a decisive parameter of seal strength.

Heterogeneous nucleation and growth of interlaced CuO nanosheets on porous nickel foams as binder-free electrode material

The monoclinic CuO has a natural tendency to grow into sheet-like structures from alkaline solutions without the need for any specialized reaction conditions or structural directing agents. We demonstrate this growth habit of CuO by heterogeneously nucleating it onto Ni foam substrate from just the ammonical solutions of Cu salts. The growth kinetics were found to be fast and, dense, interlaced thin films with an average sheet width of 20 nm can be grown by simply controlling the degree of supersaturation of the solution. Strongly adhered films with thicknesses up-to 5 μm were deposited from three different Cu salt solutions. Due to faster growth kinetics, growth time has little effect on both the film and nanosheet thickness. Detailed structural and compositional characterizations of the CuO nanosheets were made using FESEM, HRTEM, SAED, XRD and, XPS. The utility of the grown CuO nanosheets is demonstrated as a ready to use electrode for electrochemical supercapacitors. Specific capacitance in excess of 498 F/g was calculated from the Galvanostatic charge–discharge measurements collected at a current density of 0.5 A/g.

Highly water dispersible collagen/polyaniline nanocomposites with strong adhesion for electrochromic films with enhanced cycling stability

Electrochromic materials have attracted extensive attention recently due to their versatile applications in smart windows, displays, antiglare rearview mirrors, and so on. Herein we report a new electrochromic composite prepared from collagen and polyaniline (PANI) through a self-assembly assisted co-precipitation method. The introduction of hydrophilic collagen macromolecules into PANI nanoparticles makes the collagen/PANI (C/PANI) nanocomposite obtain excellent dispersibility in water, which provides good environmental-friendly solution processability. Furthermore, the C/PANI nanocomposite exhibits excellent film-forming properties and adhesion to the ITO glass matrix. The resulting electrochromic film of the C/PANI nanocomposite displays significantly improved cycling stability compared with the pure PANI film after 500 coloring-bleaching cycles. On the other hand, the composite films also exhibit yellow, green and blue polychromatic properties at different applied voltages and high average transmittance at the bleaching state. The C/PANI electrochromic material illustrates scaling potential for the application of electrochromic devices.

STRUCTURAL AND MECHANICAL PROPERTIES OF TiAlN AND TiAlN GRADIENT FILMS DEPOSITED BY REACTIVE PULSED DC MAGNETRON SPUTTERING

TiAlN and TiAlN gradient films were deposited on Si substrates by reactive pulsed DC magnetron sputtering. The crystal structure and morphology of TiAlN films were characterized via X-ray diffraction (XRD), and field emission scanning electron microscope (FE-SEM), respectively. Moreover, elemental composition, hardness, and adhesion of TiAlN films were analyzed by energy-dispersive X-ray spectroscopy (EDS), nanoindentation test, and scratch test, respectively. The TiAlN films and TiAlN gradient films showed columnar structure and cubic crystal structure with different orientation planes. The elemental mapping of TiAlN gradient films clearly demonstrated the TiAlN gradient films. TiAlN gradient films have slightly lower hardness compared to TiAlN films while adhesion of the films increases.

An anti-fibroblast adhesion and anti-inflammatory hydrogel film combined with VEGF for intrauterine adhesion prevention

Intrauterine adhesions (IUA) are a common gynecologic disease worldwide that can lead to menstrual irregularities, infertility, or repeated pregnancy loss. Biomaterials are used as a physical barrier to separate damaged uterine walls and prevent tissue adhesion. However, most biomaterials cannot prevent or even increase inflammation and fibrosis during implantation, which is crucial for IUA development, limiting their application in treatment. To address this, we developed a hydrophilic hydrogel film with a negative surface potential that can absorb excess positive proinflammatory cytokines to alleviate the inflammatory response and limit endometrial fibre formation. In vitro, the hydrogel film exhibits good biocompatibility and anti-fibroblast adhesion properties, and in vivo, they downregulate the expression level of proinflammatory cytokines and reduce the degree of fibrosis. After loading the hydrogel film with vascular endothelial growth factor (VEGF) and implanting it into the injured rat endometrial cavity, the increased local microvessels and higher endometrial thickness indicated improved endometrial regeneration during IUA treatment. In summary, the hydrogel film capable of efficiently reducing inflammation and decreasing fibrosis provides a promising strategy for treating and preventing IUA difficulties, with broad clinical application potential.

First Approach to Doping Silver into CrB2 Thin Films Deposited by DC/HiPIMS Technology in Terms of Mechanical and Tribological Properties

Doping of transition metal diborides (TMB2) films with soft metals (Ag, Au, Pt) can extend their application potential to tribological and biomedical fields. Here, a combination of direct current unbalanced magnetron sputtering (DC-UBMS) with high-power pulsed magnetron sputtering (HiPIMS) was used to synthesize silver-doped CrB2+x thin films on unheated substrates. All Ag–CrB2+x thin films were over-stoichiometric with a B/Cr ratio ranging from 2.05 to 2.30 and silver content varying from 3 at.% to 29 at.%. X-ray diffraction demonstrates the amorphous character of the structure in the case of films with silver content ranging from 0 at.% to 8 at.%. A nanocrystalline structure containing a cubic Ag phase is formed in the films with higher silver content. The highest hardness of 26.6 GPa accompanied by the highest value of elastic modulus of 362 GPa was measured in undoped CrB2.3 films. As the silver content in the Ag–CrB2+x thin films increases, the hardness and elastic modulus values gradually decrease to 7.8 GPa and 187 GPa, respectively. The friction properties of CrB2.3 films, expressed by the coefficient of friction against a steel ball of 0.72, are insufficient and limit their use in demanding industrial applications. However, silver doping significantly reduces the friction coefficient when the lowest value of 0.39 is measured in moderately hard Ag–CrB2+x films with an Ag content of 17 at.%. The scratch test shows satisfactory adhesion of films to substrates even without additional heating during deposition.

Carbon nanoparticle reinforced adhesive films as surface sensors for strain detection

Carbon nanoparticle-reinforced adhesive films have been explored as surface sensors for the detection of small strains. It has been observed that graphene nanoplatelets, GNPs, promote a significant increase of the gauge factor when compared to carbon nanotubes, CNTs (5.6 to 0.6, respectively, at low strains), due to their intrinsic 2D nature. The application as surface sensors for the monitoring of the strain field in an aluminum plate has been proven to be successful, with a repeatable signal under consecutive cycles despite some irreversibility in the first one for GNPs. Furthermore, the electrical response given by the sensors under plastic deformation of the aluminum plate was in total agreement with the mechanical response validated by numerical analysis, proving the high potential of the proposed adhesive film for sensing purposes.