Biomaterials - Intro to Biomedical Engineering

Explore atomic structure in biomaterials, including protons, neutrons, electrons, the nucleus and electron clouds, orbitals and energy levels, and the wave-particle theory of light with photons and Planck's constant.

Explore periodic trends and how to analyze the periodic table, including metals, nonmetals, halogens, and synthetic elements, plus atomic mass, atomic number, electronegativity, size, and charge.

Explore primary bonding: ionic, metallic, and covalent, via electron transfer and sharing. Learn secondary interactions: dipole-dipole, van der Waals, and hydrogen bonds that stabilize structures.

Explore how bonding types affect melting temperature, elastic modulus, and thermal expansion in biomaterials, with ionic bonds strongest and covalent and secondary bonds weaker.

Review atomic structure, periodic table trends, bonding types, and Planck's constant calculations to prepare for the quiz on energy, wavelength, and bonding effects on thermal expansion and melting points.

Review how to compute photon energy from frequency with Planck's constant, and explore atomic trends, electronegativity, and the coefficient of thermal expansion across bonds, highlighting ionic bonds.

Explore crystal structures and unit cells, focusing on simple, body-centered, and face-centered cubic lattices. Understand lattice points and the hard sphere model that determines atom counts.

Explore lattice geometry defined by positions, directions, and planes, using a fixed origin and X, Y, Z coordinates to map unit cells and derive Miller indices for lattice planes.

Practice problems on lattice directions and planes use top-left origin to determine vector components, apply intercepts and reciprocals, and use least common multiple to obtain whole numbers while handling negatives.

Recap the unit cell concepts from the quiz, contrasting the hard sphere model's location with atoms filling the lattice, then determine lattice points for cubic models and interpret plane intercepts.

Explore point defects in crystals, including vacancies, interstitials, substitutions, and impurities, and their effects on lattice stress and material properties. Learn vacancy calculations and links to processing stages.

Solve a crystal defects example on vacancies. Convert 25 °C to 298 K, use E over kT, and compute vacancy density per cm^3 from density and iron atomic mass.

Explore line defects in crystals, including edge, screw, and mixed dislocations. Understand Burgers vectors and slip planes as drivers of lattice distortions and bond rearrangement, enabling slip systems.

Explore planar defects as two-dimensional disruptions across crystal planes, including free surface atoms and grain boundaries. Learn how surface reconstruction and boundary mismatches affect conductivity, strength, and reliability in biomaterials.

Review Cristol defects: point, line, planer, and birth defects, and how vacancies, birkerts vectors (screw and edge), and bulk defects affect crystal structure and strengthening in biomaterials.

Recap section three quiz on biomaterials defects, including point defects vs dislocations, Burgers vectors, vacancies, pores from trapped gases, and crystal strengthening mechanisms.

Explain biocompatibility as a material’s ability to elicit an appropriate host response with minimal inflammation, and describe how adsorption alters surface properties and drives competitive adsorption through the Vroman effect.

Explore plasma proteins in blood that transport lipids, hormones, vitamins, and minerals, and drive coagulation and complement cascade responses, with in vitro testing to assess biocompatibility.

Learn how biocompatibility governs implant design by detailing inflammatory responses and four material classes: oxides, synthetic polymers, natural polymers, and metals, from pacemakers to dental implants and hip replacements.

The lecture outlines four main biocompatibility concerns for implants—toxicity from corrosion and degradation, blood incompatibility, bacterial infections, and inflammation—and explains their impact on patient outcomes.

Review chapter four topics on absorption, plasma proteins, and implant biocompatibility. Explore how absorption alters structure, electrical properties, body responsiveness, and implant testing, including in vivo and in vitro phases.

Recap explains how absorption changes charge and electrical properties, plus molecule size and structure, while bonds stay unchanged. It covers clotting, in vivo and in vitro implant testing, and blood compatibility.

Explore phase diagrams, solubility limits, and the phase rule to determine degrees of freedom, composition, and equilibrium in methane-water systems.

Explore binary phase diagrams, including liquid and solid phase regions, phase fields, timelines, and lever rules to determine phase compositions in binary systems such as alloys.

Examine three-phase reactions in phase diagrams, detailing five types—tactic reactions, peripatetic reactions, Mannatech reactions, eutectoid reactions, and peritectic reactions—through initial and final phase changes between liquid and solid components.

Explore the iron–carbon system with the phase diagram to determine cementite and ferrite compositions and apply the lever rule to calculate cementite content in steel.

Define phase transformation as a composition change driven by nucleation of new phases and their growth, with temperature controlling the rate in iron-carbon system contexts.

Investigate isothermal transformations and TTI diagrams to show how temperature and time govern bainite, martensite, austenite, ferrite, and cementite formation and diffusion-controlled growth.

Review the second half of chapter five in biomaterials, focusing on iron-carbon systems; read the iron-carbon graph and understand ferrite, austenite, isothermal transformations, and rate factors.

Recaps the iron-carbon quiz: delta ferrite forms at 1400 C, austenite at 900 C and is more stable at higher temperatures; perlite forms via slow cooling and relates to bainite.

Explore metals' metallic bonding and sea of electrons that give ductility, malleability, and high conductivity for biomaterial applications. Assess corrosion, wear, fatigue resistance for dental implants and joint replacements.

Learn how metals are fabricated for biomaterials via solidification and molding, and how heat, plastic deformation, grain size, and surface treatments influence strength, wear resistance, and durability of prosthetic limbs.

Examine gold-silver, cobalt, titanium, and stainless steel alloys and how their biocompatibility, strength, and corrosion resistance support dental implants, hip and cardiovascular devices, and temporary orthopedic screws and plates.

Explore total knee replacement using metal alloys to form the joint, including the four components—femoral, tibial, polyethylene spacer, and patellar—and materials cobalt chromium, titanium alloys, and polyethylene, fixed with PMA.

Explore how angioplasty uses a balloon to unblock blocked vessels and why stents keep arteries open. Learn how drug-eluting stents reduce restenosis and how imaging guides placement.

Explore the properties and classifications of metal biomaterials, including metal alloys, fabrication processes, knee replacement components, and the uses and benefits of stents.

This quiz recap highlights key biomaterials concepts, including metal properties, grain size and toughness, stainless steel limitations, and the use of titanium, cobalt, implants, and stents.

Explore ceramics as nonmetallic inorganic biomaterials, formed by covalent and ionic bonds and fired in furnaces; learn their brittleness, inertia levels, and use in bone, dental, and joint replacements.

Explore how ceramics bond mainly through ionic bonding driven by electronegativity, creating strong, short bonds that confer stability, and examine atomic ratios and coordination numbers shaping their structures.

Learn methods for processing ceramics, including sintering below melting point to form dense solids with controlled porosity for implants, plus glass formation by vitrification with annealing and tempering.

Explore silicon–oxygen tetrahedra in silicate ceramics, balancing cations to form strong, stable biomaterials. Describe glass as a noncrystalline ceramic from silica and soda-lime, with impurities enhancing properties.

Explore carbon ceramics for biomaterials, including diamond coatings for cardiac valves, graphite infrared properties and biocompatibility, and nanotubes with strong conductivity for devices and therapies.

Explore ceramics basics, bonding, and processing in this quiz review. Master radius ratio, coordination number, ceramic shapes, and topics like glass making, vitrification, sintering, carbon ceramics, and their applications.

Recap shows ceramics' suitability for bone, dental, and joint biomaterials, vs catheters; covers radius ratio and octahedral coordination; reviews melting, quenching, heating, crystal growth; notes graphite as key carbon biomaterial.

Explore point defects and imperfections in carbon ceramics, detailing vacancies, interstitials, Frankel defects, and Schottky defects and how these disruptions alter charge balance and material stability in carbon nanotubes.

Explore the properties of biomaterial ceramics, including nonreactivity to blood fluids, high compressive strength, ease of fabrication for complex shapes, and strong covalent bonds that resist slippage.

Apply three-point bending tests to determine the elastic modulus of ceramics, using a 9 mm long, 1 mm diameter sample with 900 N load and 3 mm deflection.

Explore inert, bioactive, and biodegradable ceramics for biomaterials, including aluminum oxide, zirconia, hydroxyapatite, glass ceramics, and calcium phosphates; examine applications, advantages, drawbacks, and crack resistance strategies.

Review the second half of chapter seven biomaterials with a quiz focus. Discuss point defects in ceramics, ceramic properties, testing, and applications, and apply the elastic modulus equation.

The quiz recap reviews defect types—vacancies, interstitials, Frankel defects, and the shock defects. Cover ceramics' benefits as biomaterials, three-point bending testing, and aluminum oxide's limited bone growth.

Explore polymers formed by polymerization of monomers, including linear, branched, and cross-linked structures, and copolymers like alternating and block, with emphasis on bio compatibility, toxicity, and biomaterial applications.

Explore how molecular weight determines polymer compatibility with the body, and learn to calculate degree of polymerization, number-average and weight-average molecular weight, and the disparity index to assess uniformity.

Calculate the number average molecular weight and the weight average molecular weight from monomer data. Compute the power disparity index to assess uniformity.

Examines how polymer molecular structure and additives drive mechanical properties, including viscosity, elasticity, and crystallization, through cross-linking, intermolecular forces, hydrogen bonding, and viscoelastic behavior.

Recap the quiz covers polymer tactility, weight and number average molecular weights, and the disparity index, noting linear chains as the weakest polymer property and presenting a number average calculation.

Explore polymer processing and how additives influence processing properties. Learn four main methods—compression molding, injection molding, extrusion, and blown film—and how they apply to thermoplastics and thermosets.

Explore how polymers degrade chemically through enzymatic degradation, hydrolysis, and erosion. Water-driven hydrolysis splits bonds, produces hydroxyl groups, and erosion types—surface erosion and bulk erosion—change strength and mass over time.

Explore how polymer biomaterials enable healing and medical devices, including contact lenses, sterilization kits, drug delivery systems, catheters, silicone implants, vascular grafts, and biodegradable polymers for tissue engineering.

Explore how polymer fibers and coatings enhance biomedical devices, boosting strength, wear resistance, corrosion protection, and insulation. Learn about spinning, extrusion, and ultra high molecular weight polyethylene in implants.

Review the second half of chapter eight, covering polymer processing, polymer degradation, and applications of polymers, fibers, and coatings, including fabrication methods, shapes, and processing mechanisms.

Define composites as two or more materials with different properties, combining a matrix and inclusions that transfer stresses, protect phases, and tailor strength, weight, and stiffness in biomaterials.

Explore how composite mechanical properties arise from composition, matrix and inclusions, and their distribution across shapes: particles, fibers, and platelets, affecting strength, stiffness, and ductility.

Determine the optimal fiber length via the critical length equation and assess the overall loading area for a fiber with given tensile strength, radius, and shear strength.

Review inclusion shapes—platelets, particles, and fibers—select fibers as most common, note metals are most effective in preventing creep, and evaluate fiber length relative to the critical length.

Analyze stress-strain graphs for composites, showing stage one elastic deformation and stage two plastic deformation as fibers and matrix share load under longitudinal and transverse directions.

Examine biomaterial composite applications in health care, including carbon fiber–reinforced polymers, UHMWPE, bone cement, and dental composites, emphasizing strength, creep resistance, and tensile properties.

Review quiz concepts on stress-strain graphs for composites, distinguishing stage one elastic formation from stage two plastic deformation of the matrix with fiber involvement.

Explore how biomaterials interact with vascular systems, detailing arteries, capillaries, and veins, their pressures and flow, and pathologies like stenosis, spontaneous coronary artery dissection, aneurysms, and thrombosis.

Explore vascular biomaterial applications by examining arterial grafts used to patch or replace injured arteries, choose materials like Teflon, Dacron, silicone, and polyurethanes, and address porosity, compliance, and biocompatibility challenges.

Explains the cardiac system and how the heart valves regulate blood flow. Highlights the heart's pacemaker and how plaque from coronary artery disease can cause clots, occlusion, and heart attack.

Biomaterial cardiac applications include coronary artery bypass using radial artery or saphenous vein, and stents via angioplasty to keep arteries open, plus mechanical and bioprosthetic heart valves.

Summarizes the quiz on vascular systems, thrombosis, graft materials, and coronary artery disease, clarifying capillary constant pressure, graft selection (Dacron vs silicone), and restenosis as a key stent issue.

Explore the nervous system, central and peripheral, and how biomaterials such as autografts and nerve guidance channels, with polymers and growth factors, enable nerve repair.

Discover brain implants and deep brain stimulation as biomaterial applications that modulate action potentials, address Parkinson's disease symptoms, and enable brain-computer interfaces.

Explore how biomaterials enable bone replacements, detailing materials such as titanium alloys, stainless steel, ceramics, and bone cement, and the properties required for safe, durable, corrosion-resistant implants.

Focuses on the nervous, cranial, and skeletal biomaterial applications, covering autographs, bone implants, healing effectiveness, and the advantages and limitations of various bone biomaterials.

Explore how autografts enable central nervous system repair using patient tissue, then compare nerve regeneration tests, electrophysiology, muscle staining, histology labeling, functional tests, and action potentials.