Description:DESCRIPTION:
Field of the invention:
[0001] The present disclosure generally relates to the technical field of biomedical materials and, in particular relates to bio-composite laminates that are synthesized using thermoplastic polymer polyether-ether-ketone (PEEK) combined with Portunus Pelagicus (PP) in hemp and areca nut husk (ANH) fibre reinforcement to enhance biocompatibility, sustainability and physicomechanical properties for medical implant applications.
Background of the invention:
[0002] Medical implants are essential devices in modern healthcare, providing support, replacing damaged structures, and restoring or enhancing biological functions. These implants are used in orthopaedic, dental, cardiovascular, and various other applications. The primary requirements for implant materials include biocompatibility, structural integrity, resistance to wear, and mechanical properties that match human tissues. However, achieving these requirements with traditional materials has been challenging, leading to ongoing research and development for better alternatives.
[0003] Traditionally, metals such as titanium, stainless steel, and cobalt-chromium alloys have been used for implants due to their excellent mechanical strength and durability. However, these materials pose several challenges, including high stiffness, which can lead to stress shielding and bone resorption. Metals are also prone to corrosion, especially in the physiological environment of the human body, which can lead to the release of metal ions and adverse immune responses. Additionally, metals are non-biodegradable, requiring surgical removal or posing long-term biocompatibility concerns.
[0004] Ceramics, including alumina and zirconia, have also been explored as implant materials because of their wear resistance and aesthetic appeal, especially in dental applications. However, ceramics are brittle, making them susceptible to fractures under heavy loads or impact. Their limited toughness and potential for catastrophic failure restrict their use to specific applications and often demand alternative solutions for load-bearing implants.
[0005] In response to the limitations of metals and ceramics, polymers have been investigated as potential implant materials. Among them, Polyether-ether-ketone (PEEK) has gained popularity for its mechanical strength, chemical stability, and inherent biocompatibility. PEEK is a high-performance thermoplastic with properties that make it a promising material for various medical applications, particularly in load-bearing areas such as spinal implants. However, despite its advantages, PEEK has certain limitations, where its stiffness is still higher than human bone, leading to stress shielding. Additionally, PEEK is bioinert, meaning it does not naturally promote cell adhesion and bone integration.
[0006] To address PEEK’s limitations, researchers have explored composite materials, aiming to enhance its bioactivity and mechanical properties. Reinforcing PEEK with bioactive materials such as hydroxyapatite and bio-glass has shown potential in improving bone integration and compatibility. However, these reinforcements can compromise PEEK’s mechanical properties and may pose manufacturing challenges due to poor interfacial bonding. Furthermore, some bioactive materials are brittle and can reduce the durability of the composite under physiological loading conditions.
[0007] Aiming to improve the bioactivity and mechanical characterization of the PEEK based bio-composite laminates could be reinforced with Portunus Pelagicus (PP) crab shell powder which acts as a natural hydroxyapatite need to be developed. This shows improvising the osseointegration and biocompatibility. However, these bio-composite laminates improve the mechanical characterization but depends on the better adhesion and interfacial bonding.
[0008] Natural fibres, known for their biodegradability and renewability, have gained attention as potential reinforcements for biocomposites in recent years. Hemp fibre, a sustainable and abundant resource, has demonstrated good mechanical properties, including strength and flexibility, when used in composites. Additionally, hemp fibres exhibit favorable biocompatibility, making them suitable for biomedical applications. The use of hemp in PEEK-based composites has shown promise in reducing stiffness and improving the material's overall sustainability. However, studies remain limited on its applicability in the biomedical implant sector.
[0009] Areca nut husk (ANH) fibre, another natural fibre, offers a unique composition with beneficial properties such as low density, high strength, and flexibility. Research has shown that ANH fibres have a unique porous structure, which can be advantageous in terms of enhancing mechanical properties and bioactivity. When combined with PEEK, ANH fibres can improve the composite’s toughness and resistance to fracture, while adding bioactive elements that facilitate cell attachment and tissue integration. The use of BNH fibres in polymer composites remains underexplored, particularly in medical applications, due to limited knowledge of their long-term stability and effects within the human body.
[0010] Recent developments in biocomposite materials focus on combining natural fibres with thermoplastic polymers such as PEEK to create implants that are not only mechanically resilient but also exhibit improved biocompatibility. However, current approaches have not yet achieved a satisfactory balance of sustainability, mechanical strength, and bioactivity. Existing bio-composite laminates either lack the necessary toughness and wear resistance or fail to support effective tissue integration, which is essential for long-term implant success. As such, there is a need for novel bio-composite laminates that combine the durability of synthetic polymers with the bioactivity and sustainability of natural fibres.
[0011] To address these limitations, there is a need for bio-composite laminates that are synthesized using thermoplastic polymer polyether-ether-ketone (PEEK) combined with Portunus Pelagicus (PP) crab shell in the hemp/areca nut husk (ANH) fibre reinforcements to enhance biocompatibility, sustainability, and physicomechanical properties for medical implant applications. There is also a need for bio-composite laminates that achieve enhanced physicomechanical properties and improved bioactivity by reinforcing PEEK/PP with hemp and ANH fibres, thereby promoting tissue integration while minimizing stiffness mismatch. Further, there is also a need for bio-composite laminates that utilize sustainable natural fibres such as hemp and ANH for supporting eco-friendly production, thus addressing both environmental concerns and the demand for advanced biomaterials in healthcare.
Objectives of the invention:
[0012] The primary objective of the present invention is to provide bio-composite laminates that are synthesized using thermoplastic polymer polyether-ether-ketone (PEEK) combined with Portunus Pelagicus (PP), hemp and areca nut husk (ANH) fibres to enhance biocompatibility, sustainability and physicomechanical properties for medical implant applications.
[0013] Another objective of the invention is to develop bio-composite laminates using hemp/areca fibre reinforced with PEEK/Portunus Pelagicus by optimizing the structural integrity of the bio-composite laminates while maintaining compatibility with human tissue.
[0014] The other objective of the invention is to create a PEEK-PP-hemp-ANH based bio-composite laminates that reduce the stiffness mismatch between implant materials and natural bone, thus minimizing stress shielding and promoting bone remodelling.
[0015] The other objective of the invention is to improve the bioactivity of bio-composite laminates developed for better cell adhesion and integration with human tissue, particularly for load-bearing applications.
[0016] The other objective of the invention is to achieve bio-composite laminates with superior wear resistance and durability, suitable for long-term implantation and capable of withstanding physiological loads.
[0017] The other objective of the invention is to utilize natural fibres such as hemp and ANH as reinforcements within the PEEK, thereby leveraging their biodegradability and renewable nature to support a sustainable manufacturing process.
[0018] The other objective of the invention is to facilitate the preparation method of bio-composite laminates using PEEK/Portunus Pelagicus with hemp/areca, natural fibres in a manner that ensures optimal fibre distribution and bonding within the matrix.
[0019] The other objective of the invention is to create bio-composite laminates that minimize the risk of adverse immune responses and metal ion release, as compared to traditional metal-based implants.
[0020] Yet another objective of the invention is to provide a cost-effective and scalable manufacturing process for producing bio-composite laminates, thereby enhancing accessibility for medical applications while meeting quality standards.
[0021] Further objective of the invention is to enhance the physicomechanical properties of the bio-composite laminates for a broader range of biomedical applications, such as cranial, orthopaedic, dental and spinal implants.
Summary of the invention:
[0022] The present disclosure proposes bio-composite laminates reinforced with hemp/areca fibres and PEEK/Portunus Pelagicus crab shell powder for biomedical applications. The following presents a simplified summary in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview. It is not intended to identify key/critical elements or to delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.
[0023] In order to overcome the above deficiencies of the prior art, the present disclosure is to solve the technical problem to provide bio-composite laminates that are synthesized using thermoplastic polymer polyether-ether-ketone (PEEK) combined with Portunus Pelagicus (PP) in hemp and areca nut husk (ANH) fibre reinforcement to enhance biocompatibility, sustainability and physicomechanical properties for medical implant applications.
[0024] According to an aspect, the invention proposes bio-composite laminates that achieve enhanced physicomechanical properties and improved bioactivity by reinforcing PEEK/PP with hemp and ANH fibres, thereby promoting tissue integration while minimizing stiffness mismatch. The bio-composite laminates utilize sustainable natural fibres such as hemp and ANH for supporting eco-friendly production, thus addressing both environmental concerns and the demand for advanced biomaterials in healthcare.
[0025] In one embodiment herein, the bio-composite laminate comprises 20 to 30 weight percentage of hemp fibre mat, 15 to 25 weight percentage of areca fibre mat, 0 to 2 weight percentage of polyether ether ketone (PEEK) powder, 1 to 3 weight percentage of Portunus Pelagicus (PP) crab shell powder, 40 to 50 weight percentage of a binding agent, and 3 to 7 weight percentage of a curing agent. The bio-composite laminate enhances biocompatibility, sustainability, and physicomechanical properties, thereby making the bio-composite laminates suitable for biomedical implant applications. The binding agent is epoxy resin LY556. The curing agent is hardener HY-951. The bio-composite laminate is fabricated using a hand lay-up process.
[0026] In one embodiment herein, the bio-composite laminate exhibits a compression strength of at least 31.58 MPa under a maximum compression load of 3473.58 N, along with a low compression strain of approximately 0.0137, thereby indicating superior resistance to deformation under compressive forces.
[0027] In one embodiment herein, the bio-composite laminate exhibits a tensile strength of at least 42.37 MPa under a maximum tensile load of 4660.27 N, along with a tensile modulus of 3.64 GPa, thereby demonstrating superior stiffness and load-bearing capacity under tensile forces.
[0028] In one embodiment herein, the bio-composite laminate exhibits a flexural strength of at least 71.22 MPa under a maximum load of 263.79 N, along with a maximum bending modulus of 9.254 GPa, thereby providing enhanced structural integrity and resistance to bending deformation. In one embodiment herein, the bio-composite laminate exhibits a hardness value of at least 78.25 HRB, thereby indicating superior surface resistance to deformation and enhanced wear durability.
[0029] According to an aspect, a method is disclosed for fabricating the bio-composite laminate. First, at one step, polyether ether ketone (PEEK) powder is mixed with Portunus Pelagicus (PP) crab shell powder to obtain a reinforced matrix. At another step, epoxy resin LY556 is mixed with hardener HY-951 in a ratio of 10:1 to form a resin mixture. At another step, three layers of hemp fibre mat and areca fibre mat are alternately layered while applying the resin mixture to each of the hemp fibre mat and the areca fibre mat to obtain resin-impregnated fibre layers, thereby ensuring full impregnation and proper bonding.
[0030] At another step, the reinforced matrix is dispersed onto the resin-impregnated fibre layers to obtain a homogeneously reinforced bio-composite laminate. At another step, entrapped air bubbles are removed from the bio-composite laminate using a rubber squeezer after the hand lay-up process. Further, at another step, the bio-composite laminate is cured at room temperature for a time period of at least 24 hr to achieve proper hardening.
[0031] Further, objects and advantages of the present invention will be apparent from a study of the following portion of the specification, the claims, and the attached drawings.
Detailed description of drawings:
[0032] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and, together with the description, explain the principles of the invention.
[0033] FIG. 1 illustrates a schematic representation of a bio-composite laminate, in accordance to an exemplary embodiment of the invention.
[0034] FIG. 2 illustrates a flowchart of a method for fabricating the bio-composite laminate using a hand lay-up process, in accordance to an exemplary embodiment of the invention.
[0035] FIGs. 3A to 3F illustrate screenshots, depicting preparation of bio-composite laminate samples, in accordance to an exemplary embodiment of the invention.
[0036] FIG. 4 illustrates a graphical representation, depicting compressive stress-strain behavior of the bio-composite laminate samples, in accordance to an exemplary embodiment of the invention.
[0037] FIG. 5 illustrates a graphical representation, depicting tensile stress-strain behavior of the bio-composite laminate samples, in accordance to an exemplary embodiment of the invention.
Detailed invention disclosure:
[0038] Various embodiments of the present invention will be described in reference to the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps.
[0039] The present disclosure has been made with a view towards solving the problem with the prior art described above, and it is an object of the present invention to provide bio-composite laminates that are synthesized using thermoplastic polymer polyether-ether-ketone (PEEK) combined with Portunus Pelagicus (PP) in hemp and areca nut husk (ANH) fibre reinforcement to enhance biocompatibility, sustainability and physicomechanical properties for medical implant applications.
[0040] According to an example embodiment of the invention, FIG. 1 refers to a schematic representation of a bio-composite laminate 100. In one embodiment herein, the bio-composite laminates 100 achieve enhanced physicomechanical properties and improved bioactivity by reinforcing PEEK/PP with hemp and ANH fibres, thereby promoting tissue integration while minimizing stiffness mismatch. The bio-composite laminates 100 utilize sustainable natural fibres such as hemp and ANH for supporting eco-friendly production, thus addressing both environmental concerns and the demand for advanced biomaterials in healthcare.
[0041] In one embodiment herein, the bio-composite laminate 100 is formulated with optimized weight proportions of its constituent materials to achieve superior performance characteristics. The bio-composite laminate 100 comprises 20 to 30 weight percent of hemp fibre mat 102, which provides high tensile strength, flexibility, and durability, and 15 to 25 weight percent of areca fibre mat 104, which enhances the structural integrity and impact resistance of the bio-composite laminate 100. Additionally, the bio-composite laminate 100 comprises 0 to 2 weight percent of polyether ether ketone (PEEK) powder 106, a high-performance polymer that contributes to improved mechanical strength, thermal stability, and chemical resistance, as well as 1 to 3 weight percent of Portunus Pelagicus (PP) crab shell powder 108, which enhances biocompatibility and bioactivity due to its calcium carbonate and chitin content.
[0042] Furthermore, the bio-composite laminate 100 also comprises 40 to 50 weight percent of a binding agent, specifically epoxy resin LY556, which is used to ensure strong adhesion between the fibre mats and reinforcement materials, thereby providing enhanced load-bearing capacity and durability. The bio-composite laminate 100 further comprises 3 to 7 weight percent of a curing agent, which is hardener HY-951, facilitating proper cross-linking of the resin matrix and ensuring the laminate attains the necessary mechanical rigidity and strength.
[0043] In one embodiment herein, the bio-composite laminate 100 is fabricated using a hand lay-up process, a cost-effective and energy-efficient technique that allows uniform resin distribution and optimal fibre impregnation. This process ensures effective bonding between the fibre layers and the matrix while minimizing defects such as voids and delaminations. As a result, the developed bio-composite laminate 100 exhibits enhanced biocompatibility, sustainability, and physicomechanical properties, thereby making it a highly suitable material for biomedical implant applications, where mechanical strength, long-term stability, and compatibility with biological systems are essential.
[0044] According to an example embodiment of the invention, FIG. 2 refers to a flowchart 200 of a method for fabricating the bio-composite laminate 100 using the hand lay-up process. First, at step 202, the polyether ether ketone (PEEK) powder 106 is mixed with Portunus Pelagicus (PP) crab shell powder 108 to obtain a reinforced matrix. This step ensures a uniform distribution of the reinforcement components, where the PEEK powder 106 enhances mechanical stability, and the PP crab shell powder 108 contributes bioactive properties, such as improved biocompatibility and antimicrobial effects. At step 204, epoxy resin LY556 is mixed with hardener HY-951 in a ratio of 10:1 to form a resin mixture. This precise ratio is critical to achieving the required viscosity and curing properties, thereby ensuring strong fibre-matrix adhesion. The epoxy resin acts as the binding agent 110, which provides structural integrity, while the hardener initiates the curing process as the curing agent 112, which leads to a durable composite.
[0045] At step 206, three layers of the hemp fibre mat 102 and the areca fibre mat 104 are alternately layered, with the resin mixture being applied to each layer during stacking. This step ensures that the fibres are fully impregnated with the resin, thereby facilitating effective bonding and load transfer between the fibre reinforcement and the matrix. The alternate layering of hemp fibre mat 102 and the areca fibre mat 104 optimizes the composite's mechanical properties, thereby enhancing both tensile and flexural strength. At step 208, the reinforced matrix is dispersed onto the resin-impregnated fibre layers to achieve a homogeneous bio-composite laminate 100. This step ensures even distribution of the reinforcement powders within the laminate, which prevents agglomeration and promotes uniform mechanical properties throughout the composite.
[0046] Next, at step 210, entrapped air bubbles are removed from the bio-composite laminate 100 using a rubber squeezer after the hand lay-up process. Air bubbles can create voids and reduce the composite’s strength, so this step ensures a defect-free structure with improved density and mechanical performance. Further, at step 212, the bio-composite laminate 100 is cured at room temperature for at least 24 hr to achieve proper hardening. The gradual curing process enhances polymer cross-linking, thereby ensuring that the laminate achieves maximum stiffness, durability, and adhesion without requiring high-energy processing methods.
[0047] According to an exemplary embodiment of the invention, FIGs. 3A to 3F refer to screenshots 300, 302, 304, 306, 308, and 310, respectively, depicting preparation of bio-composite laminate samples. In one embodiment herein, the bio-composite laminate samples are prepared with 2, 4, 6, 8, and 10 g of PP crab shell powder 108, combined with 8, 6, 4, 2, and 0 g of the PEEK powder 106, respectively, as represented in Table 1.
[0048] Table 1:
Sample Hemp fibre mat (g) Areca fibre mat (g) Epoxy resin (g) Hardener (g) PEEK (g) PP crab shell powder (g)
L1 105 99 204 20.4 0 10
L2 2 8
L3 4 6
L4 6 4
L5 8 2

[0049] Table 1 presents five different bio-composite laminate samples (L1 to L5) with varying proportions of polyether ether ketone (PEEK) powder 106 and Portunus Pelagicus (PP) crab shell powder 108 while maintaining consistent amounts of the hemp fibre mat 102, the areca fibre mat 104, epoxy resin (binding agent 110), and hardener (curing agent 112). The bio-composite laminate samples are prepared using hand lay-up process as shown in the screenshot 300. In one embodiment herein, the screenshot 302 depicts the sample L1, which serves as the control sample for comparison, containing 105 g of the hemp fibre mat 102 and 99 g of areca fibre mat 104, thereby ensuring a balanced natural fibre reinforcement. The binding agent 110 consists of 204 g of epoxy resin (LY556) and the curing agent 112 comprises 20.4 g of hardener (HY-951), thereby maintaining a consistent resin-to-fibre ratio. The sample L1 does not contain the PEEK powder 106 but incorporates 10 g of PP crab shell powder 108, thereby making it the highest in bioactive content. The high concentration of PP crab shell powder 108 enhances biocompatibility while contributing to the material's structural performance.
[0050] In one embodiment herein, the screenshot 304 depicts the sample L2, which follows the same base composition of 105 g of the hemp fibre mat 102 and 99 g of the areca fibre mat 104, along with 204 g of epoxy resin and 20.4 g of hardener for effective fibre-matrix adhesion. This sample introduces 2 g of PEEK powder 106, which improves mechanical strength and thermal stability, while the PP crab shell powder 108 content is reduced to 8 g. This composition balances biocompatibility with enhanced load-bearing capacity, thereby ensuring a gradual transition between mechanical reinforcement and biological functionality.
[0051] In one embodiment herein, the screenshot 306 depicts the sample L3, which maintains the same base structure with 105 g of the hemp fibre mat 102, 99 g of the areca fibre mat 104, 204 g of epoxy resin, and 20.4 g of hardener. The composition is adjusted to include 4 g of the PEEK powder 106, thereby enhancing structural rigidity and resistance to deformation, while the PP crab shell powder 108 is reduced to 6 g. This configuration optimizes both strength and biocompatibility, making it a suitable candidate for applications requiring a balance of these properties.
[0052] In one embodiment herein, the screenshot 308 depicts the sample L4, which incorporates 6 g of the PEEK powder 106, which significantly improves the laminate’s mechanical robustness, making it more resistant to external stresses. The PP crab shell powder 108 content is further reduced to 4 g, slightly lowering its bioactivity but still maintaining adequate biocompatibility. The base composition remains unchanged with 105 g of the hemp fibre mat 102, 99 g of the areca fibre mat 104, 204 g of epoxy resin, and 20.4 g of hardener. This sample is expected to exhibit superior flexural and tensile strength while retaining moderate biocompatibility.
[0053] In one embodiment herein, the screenshot 310 depicts the sample L5, which features the highest PEEK powder 106 content (8 g), providing exceptional mechanical strength, stiffness, and thermal stability. However, the PP crab shell powder 108 is minimized to 2 g, thereby making it the least bioactive among all samples while still contributing to surface properties. The base laminate remains unchanged with 105 g of the hemp fibre mat, 99 g of the areca fibre mat, 204 g of epoxy resin, and 20.4 g of hardener. This composition is ideal for applications prioritizing structural integrity over bioactivity, making L5 a strong candidate for high-load biomedical implants.
[0054] In another embodiment, the compressive strength of the bio-composite laminate samples is determined using a Universal Testing Machine (UTM) in accordance with ASTM D3410 standards. The compressive strength refers to the maximum force the material can withstand before deformation under a compression load. Each of the bio-composite laminate samples L1, L2, L3, L4, and L5 is subjected to the compression test as per the ASTM standard procedure using a UTM experimental setup. The test specimens, having dimensions of 180 mm by 12 mm, are positioned in the UTM such that the compression load is applied uniaxially along the longitudinal direction at the ends of the specimen. The load is increased gradually until the specimen fractures, thereby determining its compressive strength.
[0055] In one embodiment herein, the compressive performance of the bio-composite laminate samples L1, L2, L3, L4, and L5 is evaluated using the Universal Testing Machine (UTM) in compliance with ASTM D3410 standards. The compressive strength, strain, and modulus are systematically measured to characterize the mechanical behavior of the bio-composite laminates under axial loading conditions, with the results presented in Table 2 for comprehensive analysis.
[0056] Table 2:
Sample Max Load (N) Ultimate Compression Strength (MPa) Compression Strain at max load (mm/mm) Compression Modulus (GPa) Extension occurred at Maximum Compression Load (mm)
L1 2591.04 24.68 0.121 0.312 -1.139
L2 2589.16 24.63 0.098 1.3118 -1.085
L3 2774.89 25.23 0.0138 4.0498 -1.109
L4 2685.14 24.79 0.0124 4.091 -1.092
L5 3473.58 31.58 0.0137 4.276 -1.097

[0057] As shown in Table 2, the sample L5 exhibits the highest ultimate compressive strength of 31.58 MPa under a maximum load of 3473.58 N, which is significantly higher than sample L1 (24.68 MPa, 2591.04 N). The compression strain at maximum load for all samples is within a low range (0.0124 mm/mm to 0.0138 mm/mm), indicating minimal deformation under compressive forces. The compression modulus, which represents the stiffness of the material, is highest for L5 (4.276 GPa), followed by L3 (4.049 GPa) and L4 (4.091 GPa), thereby demonstrating enhanced load-bearing capacity and structural integrity. The negative extension values at maximum compression load indicate a gradual deformation before failure, with L1 exhibiting the highest deformation (-1.139 mm), whereas L5 (-1.097 mm) demonstrates improved dimensional stability under compression. The results confirm that modifying the PEEK and PP crab shell powder composition in the bio-composite laminates enhances compressive strength, modulus, and overall mechanical performance, thereby making them suitable for biomedical implant applications where high strength and durability are required.
[0058] According to an exemplary embodiment of the invention, FIG. 4 refers to a graphical representation 400, depicting compressive stress-strain behavior of the bio-composite laminate samples. In one embodiment herein, the graph 400 reveals variations in ultimate compressive strength, strain at failure, and modulus across different formulations, thereby demonstrating the influence of PEEK and PP crab shell powder content on the composite’s load-bearing capacity and deformation characteristics. The sample L5 exhibits the highest compressive strength, indicating superior resistance to deformation, whereas L1, serving as the control sample, presents a relatively lower strength profile. The steep slopes in the initial elastic region suggest high stiffness and load-bearing efficiency, whereas the observed variations in strain values provide insights into the fracture behavior and energy absorption of the laminates.
[0059] In another embodiment, the tensile characteristics of the bio-composite laminate samples L1, L2, L3, L4, and L5 are evaluated in accordance with ASTM D3039 standards. The tensile test specimens, having dimensions of 200 mm by 25 mm. The tensile test determines the ultimate tensile strength (UTS) and other mechanical properties by measuring the force required to fracture the composite specimens. The test involves the application of a uniaxial load along the longitudinal axis at both ends of the specimen until crack initiation and failure occur. The experimental results provide insights into the tensile performance, load-bearing capacity, and fracture behavior of the bio-composite laminates, thereby validating their suitability for biomedical implant applications.
[0060] In one embodiment herein, the tensile properties of the bio-composite laminate samples L1, L2, L3, L4, and L5 are analyzed through tensile testing conducted in accordance with ASTM D3039 standards. The experimental results are represented in Table 3, which include mechanical parameters such as maximum load, ultimate tensile strength (UTS), tensile strain at maximum load, Young’s modulus, and elongation.
[0061] Table 3:
Sample Max Load
(N) Ultimate
Tensile Strength
(MPa) Tensile Strain at max
load
(mm/mm) Young’s Modulus
(GPa) Elongation (mm)
L1 2575.87 36.80 0.12117 0.4104 0.96929
L2 3274.31 26.45 0.12567 3.118 1.06712
L3 4290.52 39.00 0.01369 4.1342 1.09655
L4 3534.19 32.13 0.01289 3.3770 1.03278
L5 4660.27 42.37 0.01715 3.6437 1.37248

[0062] According to table 3, the maximum load-bearing capacity of the bio-composite laminates is observed to range from 2575.87 N to 4660.27 N, while the UTS varies between 26.45 MPa and 42.37 MPa, depending on the composition of the laminate. The tensile strain at maximum load falls within the range of 0.12117 mm/mm to 0.01715 mm/mm, indicating variations in ductility. Furthermore, the Young’s modulus values demonstrate the stiffness characteristics of the laminates, ranging from 0.4104 GPa to 4.1342 GPa. The elongation at fracture of the samples is recorded between 0.96929 mm and 1.37248 mm, thereby providing insights into the material's deformation behavior under tensile loading. These results validate the mechanical integrity, strength, and flexibility of the bio-composite laminates, thereby confirming their potential suitability for biomedical implant applications.
[0063] According to an exemplary embodiment of the invention, FIG. 5 refers to a graphical representation 500, depicting the tensile stress-strain behavior of the bio-composite laminate samples. In one embodiment herein, the mechanical response of each sample varies based on the PEEK and PP crab shell powder compositions, influencing their strength, stiffness, and deformation characteristics. The L1 laminate (0g PEEK/10g PP) exhibits ductile failure, achieving a tensile strength of 36.80 MPa at 0.121 mm/mm strain, the highest strain among all samples, indicating high energy absorption but low stiffness (Young’s modulus: 0.41 GPa). Conversely, the L5 laminate (8g PEEK/2g PP) demonstrates the highest tensile strength (42.37 MPa) at 0.017 mm/mm strain with a Young’s modulus of 3.64 GPa, showcasing PEEK’s reinforcement effect through a steep linear elastic region followed by abrupt failure, indicative of a brittle-ductile transition.
[0064] The intermediate compositions (L2-L4) exhibit graded improvements in tensile strength (26.45-39.00 MPa) and stiffness (3.12-4.13 GPa) with increasing PEEK content, while maintaining strains below 0.013 mm/mm, thereby confirming enhanced load-bearing capacity. The stress-strain analysis establishes that bio-composite laminates containing ≥4g PEEK (L3-L5) optimize the balance between strength (≥39 MPa) and stiffness (≥3.6 GPa), which are critical for biomedical implants requiring superior fracture resistance. The L1 laminate, despite its higher strain tolerance, demonstrates lower mechanical performance, thereby confirming the biocompatibility role of PP crab shell powder at the expense of structural strength, whereas the L5 laminate’s superior tensile properties validate PEEK’s dominance in structural reinforcement, making it a preferred composition for biomedical applications requiring high strength and rigidity.
[0065] In another embodiment, the bio-composite laminate samples (L1–L5) are prepared and subjected to a three-point bending test using an INSTRON servo-hydraulic testing machine to evaluate their flexural characteristics. The test is conducted with a simply supported span length of 90 mm, thereby ensuring accurate assessment of the laminates' resistance to bending loads. The specimen samples are fabricated in accordance with ASTM D7264 standards to maintain consistency and reliability in mechanical testing. Each bio-composite laminate specimen is placed between two roller supports, forming a simply supported beam configuration, and subjected to a centralized bending load at its mid-span, thereby enabling the determination of flexural strength, stiffness, and deformation behavior under applied load conditions. The flexural properties of the bio-composite laminates (L1–L5) are evaluated and presented in Table 4.
[0066] Table 4:
Sample Max Load
(N) Maximum
Flexural
Strength
(MPa) Flexural Strain at
max load
(mm/ mm) Bending
Modulus
(GPa) Elongation (mm)
L1 150.625 41.34 0.0201 5.462 1.5086
L2 164.343 46.89 0.016 4.389 1.0456
L3 196.987 68.24 0.0089 6.811 1.0121
L4 263.785 71.22 0.0102 9.254 2.7448
L5 182.595 49.30 0.0123 6.781 3.3222

[0067] The samples exhibited a progressive increase in flexural strength corresponding to their PEEK content, with L4 (6g PEEK/4g PP) demonstrating optimal performance at 71.22 MPa under a maximum load of 263.785 N. This represents a 72% improvement over the baseline L1 sample (41.34 MPa). The bending modulus followed a similar trend, peaking at 9.254 GPa for L4, indicating enhanced stiffness from PEEK reinforcement. Notably, flexural strain decreased inversely with PEEK content, with L3 (4g PEEK/6g PP) showing the lowest strain at 0.0089 mm/mm, suggesting a transition to more brittle failure modes at higher PEEK concentrations.
[0068] The elongation data revealed an anomalous peak for L5 (8 g PEEK/2 g PP) at 3.3222 mm, potentially indicating interfacial weakening at extreme PEEK/PP ratios. These results demonstrate that intermediate PEEK compositions (4–6 g) achieve the best balance of flexural strength (68.24–71.22 MPa) and structural rigidity (6.811–9.254 GPa), making them particularly suitable for applications requiring bending resistance, such as orthopaedic implants or load-bearing prosthetics. The superior performance of L4 in both strength (71.22 MPa) and modulus (9.254 GPa) confirms that a 6:4 PEEK/PP ratio optimally reinforces the natural fibre matrix while maintaining sufficient ductility for medical applications.
[0069] In another embodiment, Rockwell hardness tester machine is utilized to gauge the Rockwell B hardness number of the fabricated bio-composite laminate samples (L1–L5). The hardness evaluation is conducted in accordance with ASTM D785 standards, thereby ensuring standardized measurement procedures. Each test specimen, measuring 30 mm by 30 mm, is placed on the loader bed at the top of the Rockwell Hardness Tester, with the gauge pre-set to zero at the initial position under minor load at the reference position. The initial principal load is applied by pulling the lever, and the dwell time is maintained for 15 s until the lift is completed. This procedure is repeated for all the bio-composite laminate samples, with hardness measurements taken at four different positions on each sample, and the average hardness values are recorded are represented in Table 5, to ensure accuracy and consistency in the material hardness assessment.
[0070] Table 5:
Sample Rockwell hardness number
L1 73
L2 64.5
L3 78.25
L4 69.5
L5 65

[0071] According to table 5, the sample L3 exhibits the highest hardness value of 78.25 HRB, surpassing the other samples. As the PEEK composition increased from 0 to 4 g, there is a corresponding increase in hardness. However, beyond 4 g (from L3 to L5), the hardness value declined, indicating a transition toward a more brittle nature. Furthermore, the samples L3, L4, and L5 consistently demonstrated higher stiffness, as evidenced by their superior moduli in compression, tensile, and flexural tests, thereby performing effectively under higher load-bearing conditions compared to L1 and L2. This trend suggests that the optimized PEEK weight proportion in L3 to L5 contributed to enhanced resistance to deformation under maximum applied loads, thereby making them structurally robust for biomedical applications.
[0072] In another embodiment, some of the mechanical properties related to various bio-composite and hybrid materials are tested and observed that variations in strength, hardness and overall performance based on fibre type, treatment, and composite formulation. Based on these parameters some of the bio-composite reinforcements with different proportions of hemp, areca with other composites such as crab shell, polypropylene, polyester and hydroxyapatites exhibits different mechanical characteristics and represented in Table 6.
[0073] The influence of varying PEEK/PP crab shell powder proportions on the sample specimens was particularly notable. The compression strength values ranged from 24.63 MPa to 31.58 MPa at a maximum load of 2.59 kN to 3.47 kN, with increasing PEEK composition reducing compression strain, thereby making the material more ductile, stiffer, and resistant to deformation under loading conditions. The L1 and L2 samples exhibited higher strain values in compression (0.121 and 0.098), tension (0.121 and 0.126), and flexural (0.0201 and 0.016) tests, indicating greater ductility. However, their stiffness, as reflected in Young’s moduli (0.41 GPa for L1 and 3.118 GPa for L2) and bending moduli (5.462 GPa for L1 and 4.389 GPa for L2), remained significantly lower. This suggests that sample specimens with 0 to 8 g of PEEK composition exhibit ductile behavior. Among all the tested specimens, those containing 4 to 8 g of PEEK demonstrated superior mechanical performance, thereby indicating an optimal balance between strength, stiffness, and load-bearing capacity based on comprehensive mechanical characterization results.
[0074] Table 6:
Bio-composite fibre material Compression strength (MPa) UTS (MPa) Flexural strength (MPa) Hardness
Hemp/Areca + PP crab shell powder + PEEK 24.63–31.58 32.13–42.37 41.34-71.22 64.5-78.25 Rockwell
Areca Husk Fibre 1.93-5.34 15.1-24.8 66.7-284.0 53.3-56.33 Rockwell
Untreated Hemp Fibre Composite 84.06-93.07 30-50 60-100 16.12-17.9 Rockwell
Chemically Treated Hemp Composite 88.53-111.05 55-80 120-180 -
Hybrid Hemp-Abaca Composite - 45-70 150–220 -
Crab Shell Hydroxyapatite 10.12 173.9 157.96 420.8 HV
Hydroxyapatite Polycaprolactone (HAp-PCL) 25.8 129 21.39 -
Areca Polyester ≈60 ≈83 ≈105–128 ≈84–88 shore D
Areca Fibre + Glass Fibre 5.2–44.5 13–23.84 2.1–5.4 88–91 BHN
Areca with PLA - 60.41 71.04 82 shore D
Coarse Areca Fibre Composite < 100 ≈ 20-33 <60 <12 Rockwell
Areca with polypropylene - 18.86–25.04 34.52–44.06 -
Synthetic Hydroxyapatite - 68.94–83.37 1.51–2.3 71.5–94.9 shore D

[0075] According to Table 6, the mechanical performance of the developed hemp/areca-PEEK-crab shell bio-composite laminates is benchmarked against existing natural and synthetic composites. The novel composite demonstrates a balanced property profile, with compression strength (24.63-31.58 MPa) superior to pure areca husk fibre (1.93-5.34 MPa) and comparable to hydroxyapatite-polycaprolactone composites (25.8 MPa), while avoiding the extreme brittleness of pure crab shell hydroxyapatite (420.8 HV hardness). Notably, the material achieves this without chemical treatment, unlike high-performance hemp composites (88.53-111.05 MPa compression) that require toxic modifiers. The flexural strength range (41.34-71.22 MPa) significantly outperforms glass fibre-reinforced areca composites (2.1-5.4 MPa) and approaches PLA-based areca composites (71.04 MPa), while maintaining better ductility than synthetic hydroxyapatite (1.51-2.3 MPa).
[0076] The Rockwell hardness (64.5-78.25 HRB) strikes an optimal balance between the excessive softness of untreated hemp (16.12-17.9 HRB) and the impractical rigidity of ceramic-filled systems (420.8 HV). This unique combination of moderate strength (32.13-42.37 MPa UTS), workable hardness, and inherent sustainability positions the invention as a viable alternative to conventional composites that typically sacrifice either mechanical performance (natural fibre systems) or eco-compatibility (synthetic reinforced composites) in biomedical applications.
[0077] The advantages of the present disclosure are evident from the discussion above. The bio-composite laminates 100 are synthesized using thermoplastic polymer polyether-ether-ketone (PEEK) combined with Portunus Pelagicus (PP), hemp and areca nut husk (ANH) fibres to enhance biocompatibility, sustainability and physicomechanical properties for medical implant applications. The bio-composite laminates 100 are synthesized using hemp/areca fibre reinforced with PEEK/Portunus Pelagicus by optimizing the structural integrity of the bio-composite laminates while maintaining compatibility with human tissue. The PEEK-PP-hemp-ANH based bio-composite laminates 100 reduce the stiffness mismatch between implant materials and natural bone, thus minimizing stress shielding and promoting bone remodelling. The bioactivity of the bio-composite laminates 100 developed for better cell adhesion and integration with human tissue, particularly for load-bearing applications. The bio-composite laminates 100 with superior wear resistance and durability, suitable for long-term implantation and capable of withstanding physiological loads.
[0078] The natural fibres such as hemp and ANH as reinforcements within the PEEK, thereby leveraging their biodegradability and renewable nature to support a sustainable manufacturing process. The preparation method of the bio-composite laminates 100 using PEEK/Portunus Pelagicus with hemp/areca, natural fibres in a manner that ensures optimal fibre distribution and bonding within the matrix. The bio-composite laminates 100 minimize the risk of adverse immune responses and metal ion release, as compared to traditional metal-based implants. The cost-effective and scalable manufacturing process for producing the bio-composite laminates 100, thereby enhancing accessibility for medical applications while meeting quality standards. The physicomechanical properties of the bio-composite laminates 100 are utilized for a broader range of biomedical applications, such as cranial, orthopaedic, dental and spinal implants.
[0079] It will readily be apparent that numerous modifications and alterations can be made to the processes described in the foregoing examples without departing from the principles underlying the invention, and all such modifications and alterations are intended to be embraced by this application.
, Claims:CLAIMS:
I / We Claim:
1. A bio-composite laminate (100) for biomedical implants, comprising:
20 to 30 weight percentage of hemp fibre mat (102);
15 to 25 weight percentage of areca fibre mat (104);
0 to 2 weight percentage of polyether ether ketone (PEEK) powder (106);
1 to 3 weight percentage of Portunus Pelagicus (PP) crab shell powder (108);
40 to 50 weight percentage of a binding agent (110); and
3 to 7 weight percentage of a curing agent (112),
wherein the bio-composite laminate (100) enhances biocompatibility, sustainability, and physicomechanical properties, thereby making the bio-composite laminates (100) suitable for biomedical implant applications.
2. The bio-composite laminate (100) as claimed in claim 1, wherein the binding agent (110) is epoxy resin LY556.
3. The bio-composite laminate (100) as claimed in claim 1, wherein the curing agent (112) is hardener HY-951.
4. The bio-composite laminate (100) as claimed in claim 1, wherein the bio-composite laminate (100) is fabricated using a hand lay-up process.
5. The bio-composite laminate (100) as claimed in claim 1, wherein the bio-composite laminate (100) exhibits a compression strength of at least 31.58 MPa under a maximum compression load of 3473.58 N, along with a low compression strain of approximately 0.0137, thereby indicating superior resistance to deformation under compressive forces.
6. The bio-composite laminate (100) as claimed in claim 1, wherein the bio-composite laminate (100) exhibits a tensile strength of at least 42.37 MPa under a maximum tensile load of 4660.27 N, along with a tensile modulus of 3.64 GPa, thereby demonstrating superior stiffness and load-bearing capacity under tensile forces.
7. The bio-composite laminate (100) as claimed in claim 1, wherein the bio-composite laminate (100) exhibits a flexural strength of at least 71.22 MPa under a maximum load of 263.79 N, along with a maximum bending modulus of 9.254 GPa, thereby providing enhanced structural integrity and resistance to bending deformation.
8. The bio-composite laminate (100) as claimed in claim 1, wherein the bio-composite laminate (100) exhibits a hardness value of at least 78.25 HRB, thereby indicating superior surface resistance to deformation and enhanced wear durability.
9. A method for fabricating a bio-composite laminate (100), comprising:
mixing polyether ether ketone (PEEK) powder (106) with Portunus Pelagicus (PP) crab shell powder (108) to obtain a reinforced matrix;
mixing epoxy resin LY556 with hardener HY-951 in a ratio of 10:1 to form a resin mixture;
alternately layering three layers of hemp fibre mat (102) and areca fibre mat (104) while applying the resin mixture to each of the hemp fibre mat (102) and the areca fibre mat (104) to obtain resin-impregnated fibre layers, thereby ensuring full impregnation and proper bonding;
dispersing the reinforced matrix onto the resin-impregnated fibre layers to obtain a homogeneously reinforced bio-composite laminate (100);
removing entrapped air bubbles from the bio-composite laminate (100) using a rubber squeezer after the hand lay-up process; and
curing the bio-composite laminate (100) at room temperature for a time period of at least 24 hr to achieve proper hardening.