Personne :
Hermawan, Hendra

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Hermawan
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Hendra
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Université Laval. Département de génie des mines, de la métallurgie et des matériaux
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0000000398411168
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ncf11858587
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Voici les éléments 1 - 10 sur 22
  • Publication
    Accès libre
    Development and characterization of silver containing calcium phosphate coatings on pure iron foam intended for bone scaffold applications
    (2018-03-28) Hermawan, Hendra; Su, Yingchao; Mantovani, D.; Tolouei, Ranna; Champagne, Sébastien; Trenggono, Adhitya
    Despite its high structural strength and degradability, the potentiality of pure iron foam for bone scaffolds is low due to its lack of surface bioactivity. This work aims to provide a surface bioactivity to the iron foam by developing a calcium phosphate (CaP) conversion coating. Silver (Ag), known for its antibacterial property, was then incorporated onto the CaP coating via co-deposition (Ag/CaP-c) and post-treatment (Ag/CaP-p). By tuning the Ca/P ion ratio and Ag concentration during the coating process, an optimum coating parameter was obtained. All coatings were found to enhance mineralization ability and mechanical integrity of the iron foam over time. Electrochemical and immersion tests indicated that the coatings regulated the degradation rate of the iron foam via a variation of coating resistance and capacitance. Silver ions were released slowly from the Ag/CaP coating during the immersion test indicating a potential long-term antibacterial property of the coating. Details on the coating design and process optimization, the effects of three different simulated physiological solutions, and the mechanical property of the coated iron foam are discussed in this report.
  • Publication
    Accès libre
    In vitro degradation of absorbable zinc alloys in artificial urine
    (MDPI, 2019-01-18) Ghali, Edward; Mostaed, Ehsan; Vedani, Maurizio; Hermawan, Hendra; Champagne, Sébastien; Safizadeh, Fariba
    Absorbable metals have potential for making in-demand rigid temporary stents for the treatment of urinary tract obstruction, where polymers have reached their limits. In this work, in vitro degradation behavior of absorbable zinc alloys in artificial urine was studied using electrochemical methods and advanced surface characterization techniques with a comparison to a magnesium alloy. The results showed that pure zinc and its alloys (Zn–0.5Mg, Zn–1Mg, Zn–0.5Al) exhibited slower corrosion than pure magnesium and an Mg–2Zn–1Mn alloy. The corrosion layer was composed mostly of hydroxide, carbonate, and phosphate, without calcium content for the zinc group. Among all tested metals, the Zn–0.5Al alloy exhibited a uniform corrosion layer with low affinity with the ions in artificial urine.
  • Publication
    Accès libre
    Conception, développement et validation d'alliages métalliques dégradables utilisés en chirurgie endovasculaire
    (2009) Hermawan, Hendra; Mantovani, D.; Dubé, Dominique
    Ce projet de doctorat a permis pour la première fois de concevoir, réaliser et étudier le potentiel des matériaux métalliques biodégradables. En effet, le fer pur et les alliages de magnésium avaient été évalué entre 2001 et 2003 quant à la possibilité de devenir des biomatériaux dégradables. Ces travaux ont cependant montré que les propriétés mécaniques et du comportement en dégradation de ces alliages devaient être améliorées pour répondre aux besoins cliniques. Dans cette perspective, une série de nouveaux alliages du système Fe–Mn ont été élaborés et étudiés. L'objectif est d'obtenir des propriétés physiques et mécaniques similaires à celles de l'acier inoxydable 316L (SS316L) et un comportement à la dégradation mieux adapté à l’environnement physiologique humain que le fer pur et les alliages de magnésium. Quatre alliages de fer contenant 20 à 35% de manganèse ont été préparés par les techniques de la métallurgie des poudres, puis par la suite ils ont subi plusieurs cycles de laminage à froid et de frittage. Les résultats de ces travaux ont montré que la microstructure des alliages Fe–Mn est principalement composée d’une phase austénitique et de traces de phases martensitiques chez les alliages contenant moins de manganèse. Les alliages sont non–ferromagnétiques, leur susceptibilité magnétique étant inférieure à celle du SS316L. Contrairement au SS316L, cette susceptibilité magnétique demeure constante après écrouissage. Les propriétés mécaniques des alliages Fe–Mn approchent celles du SS316L. Leur limite d'élasticité diminue de 420 à 210 MPa et leur allongement à la rupture augmente de 5 à 32% quand la teneur en manganèse augmente de 20 à 35%. Pendant un essai in vitro, les alliages se dégradent par corrosion. Les produits de dégradation sont des couches d’hydroxydes de fer et de calcium/phosphore. Les taux de corrosion mesurés sont plus grands que celui du fer pur, mais plus faibles que celui de l’alliage de magnésium. Le relargage des ions de fer et de manganèse dans la solution est limité par les couches de produits de dégradation. Les essais de viabilité cellulaire ont montré que les alliages de Fe–Mn inhibent faiblement l’activité métabolique des fibroblastes. Tous ces éléments confirment le potentiel des alliages Fe–Mn pour la fabrication d’un biomatériau dégradable biocompatible.
  • Publication
    Accès libre
    Processing of Zn-3Mg alloy by equal channel angular pressing for biodegradable metal implants
    (Elsevier, 2017-07-29) Dambatta, Murtala Sule; Hermawan, Hendra; Izman, Sudin; Kurniawan, Denni
    Zn-based alloys have been studied as new biodegradable metals owing to its slower corrosion rate compared to Mg-based alloys and its high potential for mechanical properties improvement. The present work attempts to improve mainly the mechanical properties of a eutectic Zn-3Mg alloy via equal channels angular pressing (ECAP). Cast Zn-3Mg alloy was homogenized at 370 °C for 15 h and quenched in water before subjected to 2 steps ECAP process. Results showed that the process decreases the alloy’s grain size from 48 µm in the as cast to 1.8 µm after 2-passes of ECAP. A remarkably increase of yield strength, tensile strength and elongation was achieved from 65 MPa, 84 MPa and 1.3% (as cast) to 205 MPa, 220 MPa and 6.3% (2-ECAP), respectively. Corrosion rate of the alloy was fairly altered from 0.30 mm/year (as cast) to 0.24 mm/year (2-ECAP). The combination of homogenization and ECAP is therefore viewed as a potential process to improve mechanical properties of Zn-Mg alloys.
  • Publication
    Accès libre
    Monitoring magnesium degradation using microdialysis and fabric-based biosensors
    (Science China Press, 2017-08-08) Mohamad, Su Natasha; Hermawan, Hendra; Malon, Radha S. P.; Wicaksono, Dedy H. B.; Córcoles, Emma P.
    This paper describes the development of a monitoring system capable of detecting the concentration of magnesium ions (Mg2+) released during the degradation of magnesium implants. The system consists of a microdialysis probe that samples fluid adjacent to the implant and a catalytic biosensor specific to Mg2+ ions. The biosensor was fabricated on a cotton fabric platform, in which a mixture of glycerol kinase and glycerol-3-phosphate oxidase enzymes was immobilized on the fabric device via a simple matrix entrapment technique of the cotton fibers. Pure magnesium was used as the implant material. Subsequently, the concentration of ions released from the degradation of the magnesium specimen in Ringer’s solution was evaluated using cyclic voltammetry technique. The device demonstrated a pseudo-linear response from 0.005 to 0.1 mmol L−1 with a slope of 67.48 μA mmol−1 L. Detectable interfering species were lesser than 1% indicating a high selectivity of the fabric device. Furthermore, the device requires only 3 μL of fluid sample to complete the measurement compared to spectroscopic method (±50 μL), hence providing a higher temporal resolution and reduced sampling time. The system could potentially provide a real time assessment of the degradation behavior, a new studied aspect in biodegradable metals research.
  • Publication
    Accès libre
    Mechanical and corrosion properties of partially degradable bone screws made of pure iron and stainless steel 316L by friction welding
    (Springer, 2017-07-21) Kafrawi Nasution, Ahmad; Hermawan, Hendra; Ulum, Mokhamad Fakhrul; Mohammed Rafiq Abdul Kadir
    This paper reports a series of in vitro, ex vivo and in vivo mechanical and corrosion studies of pin and screw prototype made of friction welded pure iron and 316L type stainless steel aiming to evaluate the applicability of the partially removable bone screws. Results showed that the pin possesses bending, tensile and torsional strengths of 1706±147, 666±7 and 0.34±0.03 MPa, respectively. The pin degraded at an average weight loss rate of 17.15×10−5 g cm−2 day−1 and released Fe ions at an average concentration of 2.38 ppm. Plastic deformation induced by torsion increased the corrosion rate of the pin from 0.0014 to 0.0137 mm year−1. The maximum pull-out load of the screw prototypes was 3800 N with a calculated failure strength by shear load equal to 22.2 kN which is higher than the strength of the cortical bone. Detailed analysis of the rat’s blood cells during 60 days of the pin implantation indicated a normal response with low neutrophils/ lymphocytes ratio of 0.3‒0.5. Iron ion concentration in the rat’s blood slightly increased from 55 to 61 ppm without affecting the tissue recovering and healing phase. Histological evaluation confirmed the presence of macrophage cells as a normal response to the released iron particles around the iron section of the pin.
  • Publication
    Accès libre
    Current status and perspectives of zinc-based absorbable alloys for biomedical applications
    (Elsevier, 2019-07-24) Hernández-Escobar, David; Hermawan, Hendra; Champagne, Sébastien; Yilmazer, Hakan; Dikici, Burak; Boehlert, Carl J.
    Absorbable metals have the potential to serve as the next generation of temporary medical implant devices by safely dissolving in the human body upon vascular tissue healing and bone regeneration. Their implementation in the market could greatly reduce the need of costly and risky additional surgeries for either implant replacement or removal, often required in current permanent implants. Despite the extensive research done over the last two decades on magnesium (Mg) and iron (Fe) based alloys, they have not generally shown a satisfactory combination of mechanical properties, biocompatibility and controlled degradation rate in the physiological environment. Consequently, zinc (Zn) based alloys were introduced in the last few years as alternative materials to overcome the limitations of Fe and Mg-based alloys. The blend of different alloying elements and processing conditions have led to a wide variety of Zn-based alloys having tunable mechanical properties and corrosion rates. This review provides the most recent progress in the development of absorbable Zn-based alloys for biomedical implant applications, primarily for cardiovascular and orthopedic devices. Their biocompatibility, processability and metallurgical aspects, as well as their mechanical behavior and corrosion properties are presented and discussed, including their opportunities, limitations and future research directions.
  • Publication
    Accès libre
    Structure, degradation, drug release and mechanical properties relationships of iron-based drug eluting scaffolds : the effects of PLGA
    (Elsevier Science, 2018-09-12) Yusop, Abdul Hakim; Hermawan, Hendra; Sarian, Murni Nazira; Al-Fatihhi bin Mohd Szali Januddi, Mohd; Uddin Ahmed, Qamar; Mohammed Rafiq Abdul Kadir; Hartanto, Djoko; Nur, Hadi
    The effects of poly(lactic‑co‑glycolic acid) (PLGA) on structure, degradation, drug release and mechanical properties relationships of iron-based drug eluting scaffolds have been studied comprehensively. The porous structure of the iron has been incorporated with the curcumin-loaded PLGA (CP) particles through dipping method to produce CP-coated porous Fe (CP-Fe). The CP-Fe degradation has been escalated with the increase of PLGA composition due to the hydrolysis of PLGA. The degradation of iron substrate triggered the kinetics of curcumin release as there was a direct correlation between the curcumin release rate and the degradation rate of the CP-Fe scaffold. The stiffness of the CP particles and the interfacial interactions developed between the CP coating and iron surface have enhanced scaffolds' mechanical strengths. The curcumin released from the scaffold significantly arrested osteosarcoma cells growth. It is demonstrated that the PLGA played an important role to control the scaffold degradation and curcumin release as well as enhancing the mechanical properties of the drug device as an integrated system for favorable scaffold-based drug design.
  • Publication
    Accès libre
    Novel antibacterial biodegradable Fe-Mn-Ag alloys produced by mechanical alloying
    (Elsevier, 2018-03-11) Sotoudeh Bagha, Pedram; Hermawan, Hendra; Sheibani, Saeed; Salehi, Mehrdad; Ebrahimi-Barough, Somayeh
    Various compositions and synthesis methods of biodegradable iron-based alloys have been studied aiming for the use of temporary medical implants. However, none is focused on nano-structured alloy and on adding antibacterial property to the alloy. In this study, new Fe-30Mn-(1–3)Ag alloys were synthesized by means of mechanical alloying and assessed for their microstructure, mechanical properties, corrosion rate, antibacterial activity and cytotoxicity. Results showed that the alloy with 3 wt% Ag content displayed the highest relative density, shear strength, micro hardness and corrosion rate. However, optimum cytotoxicity and the antibacterial activity were reached by the alloy with 1 wt% Ag content. The compositional and processing effects of the alloys' properties are further discussed in this work.
  • Publication
    Accès libre
    In-Vivo Corrosion Characterization and Assessment of Absorbable Metal Implants
    (MDPI AG, 2019-04-26) Ulum, Mokhamad Fakhrul; Hermawan, Hendra; Caesarendra, Wahyu; Alavi, Reza
    Absorbable metals have been introduced as materials to fabricate temporary medical implants. Iron, magnesium and zinc have been considered as major base elements of such metals. The metallurgical characterization and in-vitro corrosion assessment of these metals have been covered by the new ASTM standards F3160 and F3268. However, the in-vivo corrosion characterization and assessment of absorbable metal implants are not yet well established. The corrosion of metals in the in-vivo environment leads to metal ion release and corrosion product formation that may cause excessive toxicity. The aim of this work is to introduce the techniques to assess absorbable metal implants and their in-vivo corrosion behavior. This contains the existing approaches, e.g., implant retrieval and histological analysis, ultrasonography and radiography, and the new techniques for real-time in-vivo corrosion monitoring.