Chapter Four · failure evidence
What Additive Manufacturing & 3D Printing got wrong, from 84 dissertations
The records evaluate various additive manufacturing techniques and demonstrate frequent issues spanning mechanical defects, processing instabilities, and biological incompatibilities. Across numerous applications, 3D printing approaches were frequently outperformed by conventional fabrication methods or abandoned due to geometric and material limitations. These records come from PhD theses at 26 institutions, 2021 to 2026. Each links to its thesis. They were extracted by language models reading the full text, so treat each as a lead to read, not a verdict.
Surface roughness, poor resolution, and dimensional inaccuracies prevent precision assembly and fluid containment
Extruded and sintered components frequently exceeded specified geometric tolerances, leading to assembly interference, mating failures, and persistent fluid leakage in microfluidic channels. Molds and structural surfaces exhibited excessive roughness and non-planarity that impeded PDMS casting, demolding, and bonding.
Tried and failed
direct additive manufacturing without dimensional tolerance offsets applied to interlocking mechanical mold assemblies. Reason: extrusion width caused convex features to be oversized and concave slots undersized, preventing assembly
A MANUFACTURING PROCESS TO IMPLEMENT TRANSONIC COMPRESSOR ENDWALL CASING TREATMENTS · Calhoun
Considered and rejected
Considered and rejected: Rejected direct 3D printing of enclosed microchannels due to resin surface roughness, inability to bond glass/PDMS, and printer dimensional variability.
Novel engineering and characterization of sensing materials and fluidic devices for neuroscience · Imperial
Considered and rejected
Considered and rejected: 3D printing of dispersion modules was rejected due to persistent joint leakage when operated under pressure
Unlocking the Rare Earth Elements Potential of Allanite: A Comprehensive Study of Beneficiation and Leaching · Virginia Tech
Tried and failed
liquid metal jet printing applied to precision metal casing rings. Reason: Severe dimensional variance, high surface roughness, and rapid nozzle degradation prevented tight-tolerance fabrication.
DUCTED FLOW CONTROL IN A TRANSONIC COMPRESSOR, METHODS AND ANALYSIS · Calhoun
Tried and failed
3D printing precision fluid-dispensing mechanical parts applied to precision bubble generation mechanism. Reason: insufficient dimensional accuracy and tolerances of 3D-printed components caused mechanism failure
Robots Who Live for Themselves: Exploring Ludic HRI Through Character-Driven Robot Design · Cornell
Tried and failed
direct metal laser melting fabrication applied to precision metal casing component. Reason: as-built outer dimensions exceeded specified tolerances, preventing physical assembly
DUCTED FLOW CONTROL IN A TRANSONIC COMPRESSOR, METHODS AND ANALYSIS · Calhoun
Considered and rejected
Considered and rejected: Rejected Fused Deposition Modeling (FDM) printing due to insufficient resolution to prevent fluid leaking.
Novel engineering and characterization of sensing materials and fluidic devices for neuroscience · Imperial
Tried and failed
SLS 3D printed molds for PDMS casting applied to magnetic concentrator funnel fabrication. Reason: Cure inhibition of PDMS, high surface roughness, and dimensional variability of mold outlets.
Density-shift Immunomagnetic Separation for Pathogen Retrieval from Complex Media · MIT
Tried and failed
3D printing and waterjet machining applied to microscale stick-slip friction contacts. Reason: Poor edge definition, high surface roughness, and slanted cuts prevented reliable microscopic frictional contact.
A Compact Piezoelectric Tilt Table for Cryogenic Electron Microscopy · Harvard
Tried and failed
fused deposition modeling 3D printing applied to microfluidic flow cells. Reason: high surface roughness and poor structural strength caused fluid leaks
Engineering and characterisation of optical nucleic acid sensors · Imperial
Tried and failed
consumer 3D printing applied to standard tactile braille production. Reason: insufficient print resolution and bed size constraints failed tactile spacing standards
Tried and failed
3D-printed and milled molds for soft lithography applied to microfluidic channel fabrication. Reason: Molds produced via stereolithography, FDM, and CNC milling failed to yield functional PDMS channels
Tried and failed
3D printing microfluidic channels applied to acoustofluidic device fabrication. Reason: insufficient printing precision and material acoustic incompatibility with the transducer
Design and development of cost-effective and portable 3D printed biomedical equipment · Iowa State
Lost to a baseline
High-frequency 3D printing of standard continuous-phase kinoforms suffered from insufficient z-axis printer resolution to resolve tiny thickness step differences at high ultrasound frequencies.
Exploiting the Interplay of Acoustic Waves and Fluid Motion for Particle Manipulation · DukeSpace
Considered and rejected
Considered and rejected: FDM 3D printing of mixing geometries rejected due to poor internal surface finish/resolution and low thermoplastic melting temperatures during the exothermic reaction.
Considered and rejected
Considered and rejected: Rejected SLA and FDM 3D printing for negative molds due to surface artifacts preventing plasma bonding of PDMS
In Vitro Remodeling of Extracellular Matrix Following Mild Traumatic Brain Injury · Virginia Tech
Considered and rejected
Considered and rejected: Rejected Fused Filament Fabrication (Stratasys Fortus 400mc / Ultem 1010) due to poor layer surface finish hindering demolding
An Exploration of Rapid Tooling in Low-Cost Bead Foam Molding Applications · Virginia Tech
Considered and rejected
Considered and rejected: Rejected Scotch-tape rapid prototyping and 3D printed molds for master fabrication due to edge degradation and precision loss over repeated soft lithography cycles.
SPR STUDIES OF N-HETEROCYCLIC CARBENE ADSORPTION KINETICS AND THE APPLICATION OF FIBER FABRY-PÉROT CAVITIES IN CHEMISTRY · Queens University Institutional Repository
Considered and rejected
Considered and rejected: Rejected additive manufacturing (AM) for calibration standard fabrication due to unsatisfactory surface finishing quality.
Areal artefact manufacturing using SPDT · Cranfield
Considered and rejected
Considered and rejected: FDM 3D printing and waterjet cutting rejected due to severe surface roughness, slanted kerf, and loss of fine tooth geometry.
A Compact Piezoelectric Tilt Table for Cryogenic Electron Microscopy · Harvard
Considered and rejected
Considered and rejected: Single-part 3D printed fluidic manifold rejected in favor of a hybrid 3D-printed manifold with an etched Si capping layer due to 3D printing surface non-planarity causing fluid flow-bypass.
DENSE INTERCONNECTION AND ADVANCED COOLING TECHNOLOGIES FOR 2.5D AND 3D HETEROGENEOUS INTEGRATED CIRCUITS · Georgia Tech
Considered and rejected
Considered and rejected: Rejected FDM 3D printing for smart packaging due to high surface roughness (~25x higher than SLA) interfering with post-print metallization
Additive manufacturing solutions for application-specific millimeter-wave wireless system design and packaging · Georgia Tech
Considered and rejected
Considered and rejected: SLM direct 3D printing in aluminum was abandoned for lost-wax casting in sterling silver due to surface roughness and inter-ring short circuits
Subwavelength resonators for performance enhancement in room-temperature solid-state masers · EPFL
Deposition instability, rheological collapse, and nozzle clogging disrupt direct ink and extrusion processes
Inks, hydrogels, and polymer filaments suffered from inconsistent extrusion, nozzle clogging, and unconstrained spreading due to insufficient viscosity or improper shear properties. Material oozing during travel moves and trapping of unpolymerized resin in internal features compromised intricate geometric structures.
Tried and failed
semi-solid extrusion 3D printing applied to low-concentration single-component biopolymer hydrogels. Outcome: unstable. Reason: insufficient viscosity and low yield stress caused spreading and loss of shape fidelity post-deposition
Semi-solid extrusion-based 3D printing of biopolymer hydrogels and their applications in food · Iowa State
Tried and failed
fused deposition modelling extrusion of neat biopolymer applied to polybutylene succinate 3D printing filament. Outcome: unstable. Reason: filament extrusion instability and poor dimensional accuracy during deposition
Considered and rejected
Considered and rejected: Rejected 3D-printed extrusion nozzles after initial trials because extrusion became inconsistent at fine gauge sizes and high solid loadings.
ADDITIVE MANUFACTURING OF CONDUCTIVE PARTS USING METAL-POLYMER COMPOSITES · Calhoun
Tried and failed
stereolithography 3D printing of negative microcavity features applied to micropatterned mold fabrication. Reason: uncured liquid resin remained trapped and clogged within microscale negative hole features during printing
Programming Complex Alignment in Engineered Cardiac Tissue · Harvard
Tried and failed
extrusion 3D printing of hydrogel scaffolds applied to porous GelMA tissue engineering constructs. Outcome: unstable. Reason: low concentration collapsed during printing, whereas higher concentration merged and occluded designed micro-pores
Bioengineered scaffolds as a tool to decode the complexity of cancer cell interactions in vivo · Imperial
Considered and rejected
Considered and rejected: Rejected direct-write extrusion (DIW) printing for complex living objects due to limitations in geometrical complexity and connectivity relative to vat photopolymerization.
Tried and failed
Direct extrusion via sub-millimeter nozzle diameters applied to High-viscosity photocurable polymers. Outcome: unstable. Reason: Narrow nozzles caused clogging and pressure-induced distortion, while wider nozzles prevented fine resolution
Design of a 3D UV-Silicone Printing Machine for Complex Geometry Printing · Texas Tech
Tried and failed
single-pass inkjet printing of thick dielectric layers applied to thick polymer film deposition. Outcome: unstable. Reason: Excessive wet volume led to bulging and non-uniform convex coffee-ring thickness profiles.
Additive manufacturing solutions for application-specific millimeter-wave wireless system design and packaging · Georgia Tech
Tried and failed
direct ink writing extrusion 3D printing applied to photocurable viscous prepolymer resins. Outcome: unstable. Reason: slicer and extrusion control limitations caused unwanted material oozing and over-deposition during travel moves
3D Printed Biodegradable And Shape Memory Polymer Poly(Glycerol Dodecanedioate) (PGD) For Soft Tissue Reconstruction · Georgia Tech
Tried and failed
high speed material extrusion on tacky substrate applied to viscous ink additive manufacturing. Outcome: unstable. Reason: viscoelastic dragging and poor interfacial adhesion caused severe filament shortening during deposition
Multimaterial 3D/4D Printing by Integrating Digital Light Processing and Direct Ink Writing · Georgia Tech
Tried and failed
direct-write extrusion of molten microstructures applied to high-density micro-needle arrays. Reason: thermal dissipation and nozzle clearance caused re-melting of adjacent features above critical aspect ratios
MOLTEN-BASED 3-D DIRECTWRITE FABRICATION OF MICRO STRUCTURES · Georgia Tech
Tried and failed
reducing extrusion line width applied to material extrusion 3D printing. Outcome: worse than baseline. Reason: deteriorated surface quality and required more toolpath passes to cover the target area
The influence of microscopic features on the self-cleaning ability of 3D printed fabric-like structures · Cranfield
Tried and failed
zig-zag toolpath infill strategy applied to material extrusion 3D printing. Reason: machine vibrations caused rough surface finish, structural defects, and gaps
Tried and failed
stereolithography 3D printing of deep narrow channels applied to sacrificial investment casting patterns. Reason: resin trapped or overcured in high-aspect-ratio holes prevented complete channel formation and circular geometry
Applications of Investment Casting as a Manufacturing Process for Injection Mold Tooling · MIT
Tried and failed
embedded 3D printing in gel matrices applied to sintered composite auxetic structures. Reason: pervasive cracking throughout the sintered parts during the post-printing sintering process
Direct ink writing of ceramic composites · Imperial
Considered and rejected
Considered and rejected: Direct 3D printing of hydrogels abandoned in favor of casting resin inside 3D-printed and degassed silicone (Mold Max 10T) moulds due to printing instability and incomplete curing.
Development of a novel tissue expander for non-keratinised epithelial tissue · University of Nottingham Repository
Thermal warpage, curing shrinkage, and peel forces distort thin-walled and flexible geometries
Unsupported thin walls and elastomeric struts warped or tore apart during post-print curing and vat separation peel cycles. Inherent thermal residual stresses and uneven shrinkage caused severe distortion, recoater collisions, and dimensional loss compared to nominal designs.
Tried and failed
stereolithography 3D printing with elastomeric resin applied to variable stiffness soft robotic skeletons. Reason: support structure removal left surface defects that altered mechanical stiffness
Manipulating Stiffness of Biomechanical Systems to Train Muscle · MIT
Tried and failed
FDM 3D printing and vacuum forming applied to ultra-thin corrugated aerodynamic structures. Reason: exceeded minimum thickness limits resulting in frequent defects and poor structural integrity
Comparative wind tunnel evaluation of a bio-inspired corrugated wing · Imperial
Tried and failed
photopolymer 3D printing of thin-walled geometries applied to rigid structural resin components. Outcome: unstable. Reason: thin features warped and distorted during UV post-print curing due to uneven shrinkage
ARRAYS OF MILLIMETER-SCALE RUBBER COMBUSTION ENGINES · Cornell
Tried and failed
direct additive manufacturing of angled thin elastomeric structures applied to flexible robotic struts. Outcome: unstable. Reason: unsupported thin elastomeric struts cannot maintain structural shape during printing
CONTROLLING STIFFNESS WITH TENDON - FLUID TENSEGRITY · Cornell
Considered and rejected
Considered and rejected: FDM printing and vacuum forming were rejected due to inability to achieve ≤0.4 mm thickness with sufficient structural integrity and reproducibility.
Comparative wind tunnel evaluation of a bio-inspired corrugated wing · Imperial
Considered and rejected
Considered and rejected: Uniform rigid 3D printing was rejected because it could not decouple structural bending stiffness from aerodynamic profile geometry.
On scaling and system identification of flexible aircraft dynamics. · Cranfield
Considered and rejected
Considered and rejected: Rejected 0.5 mm thick fins with 1.5 mm spacing in 3D-printed bobbins due to 3D printing fabrication limits and required structural integrity.
Development of high power medium-frequency transformers · UT Austin
Tried and failed
selective laser sintering of thin flexures applied to compliant origami joint fabrication. Reason: laser resolution limits minimum feature thickness, resulting in excessively high joint stiffness
Extending human interaction capabilities with soft robotics · EPFL
Tried and failed
laser powder bed fusion additive manufacturing applied to sub-millimeter thin wall fabrication. Reason: residual stress and thermal warpage caused recoater-part collisions below 500 µm feature sizes
Tried and failed
stereolithography printing with low-modulus elastomeric resin applied to cellular lattice structures. Reason: vat adhesion peel forces during separation tore delicate low-stiffness layers apart during printing
Development and mechanical characterisation of additively manufactured lattice structures · Imperial
Tried and failed
stereolithography 3D printing with thin walls applied to custom intraoral hollow prostheses. Reason: 0.7 mm wall thickness was too thin to fabricate reliably using SLA 3D printing
Design and Manufacturing of a Novel Intraoral Prosthesis for Obstructive Sleep Apnea · MIT
Tried and failed
photopolymer 3D printing with post-print curing applied to high-aspect-ratio thin microstructures. Outcome: unstable. Reason: differential shrinkage during post-print UV curing causes mechanical warping of thin unsupported features
HIGH VOLTAGE PYROELECTRIC GENERATION, ELECTROSTATIC ACTUATORS, AND SENSING IN MICROSYSTEMS · Cornell
Tried and failed
direct ink writing onto flexible porous substrates applied to biomass composite paste printing. Reason: drying shrinkage caused severe warping, curling, and part breakage during substrate release
DeepGreen: Additive Manufacturing of Carbon-Negative Algae Biocomposites · Harvard
Lost to a baseline
DLP 3D-printed cylinders exhibited significantly lower volume (74.6 ± 5.4 mm³) compared to molded/lasercut cylinders (81.2 ± 2.6 mm³) and extrusion-printed cylinders (87.5 ± 3.7 mm³) relative to nominal design.
3D Printed Biodegradable And Shape Memory Polymer Poly(Glycerol Dodecanedioate) (PGD) For Soft Tissue Reconstruction · Georgia Tech
Interlayer delamination, structural anisotropy, and mechanical weakness degrade load-bearing performance
Printed parts displayed poor interlayer bonding and high directional anisotropy that triggered premature brittle fractures along layer interfaces under mechanical stress. Inadequate thermal environments and suboptimal printing temperatures yielded inferior wear resistance, tensile strength, and strain at break compared to molded counterparts.
Tried and failed
fused deposition modeling 3D printing applied to mechanical metamaterial unit cells. Reason: interlaminar anisotropy caused brittle fracture between printed layers at flexure intersections under out-of-plane loading
Functional mechanical metamaterials - development of programmable mechanical structures · Imperial
Tried and failed
extrusion printing at manufacturer recommended temperatures applied to thermoplastic polymer tensile specimens. Outcome: worse than baseline. Reason: suboptimal interlayer bonding and thermal profile yielded tensile strength significantly below advertised specifications
Tried and failed
FDM 3D printing of waveguide antenna structures applied to horn antennas. Reason: Structural delamination, edge sagging, and mechanical joint separation between the waveguide and flare.
The development of a drone radar system · Imperial
Tried and failed
material extrusion 3D printing applied to polyethylene polymer blends. Outcome: worse than baseline. Reason: 3D printed specimens showed higher wear factors and lower wear resistance than injection molded equivalents
Influence of Texture on Wear Behavior of 3D Printed HDPE/UHMWPE Bioimplant Material · Georgia Tech
Tried and failed
fused deposition modeling at standard processing temperature applied to immiscible biopolymer blend filaments. Reason: severe delamination, warpage, and poor bed adhesion during horizontal printing
Considered and rejected
Considered and rejected: Rejected FDM printing for 3D anisotropic unit cells because anisotropic layer bonding caused brittle fracture in one of the three principal axes
Functional mechanical metamaterials - development of programmable mechanical structures · Imperial
Considered and rejected
Considered and rejected: Rejected open-air 3D printing and cardboard enclosures due to inadequate thermal control causing layer delamination and non-solid prints.
Feasibility study of thermoplastic nanocomposite for ESD applications using additive manufacturing · TXST Digital Repository
Considered and rejected
Considered and rejected: Rejected direct mSLA printing of PU/PEMA hinges for static testing due to rapid fatigue and brittle fracture at surface defects
Lost to a baseline
Photocured 3D printed APGD exhibited lower strain at break (41.5 ± 8.3% for DLP, 45.0 ± 5.2% for extrusion) compared to molded/lasercut baseline samples (63.2 ± 23.7%).
3D Printed Biodegradable And Shape Memory Polymer Poly(Glycerol Dodecanedioate) (PGD) For Soft Tissue Reconstruction · Georgia Tech
Lost to a baseline
Extrusion 3D printed APGD exhibited lower shape fixity ratio (77.4 ± 4.7%) compared to molded/lasercut baseline samples (92.4 ± 6.0%).
3D Printed Biodegradable And Shape Memory Polymer Poly(Glycerol Dodecanedioate) (PGD) For Soft Tissue Reconstruction · Georgia Tech
Economic, throughput, and scalability deficits make 3D printing less viable than conventional methods
Production runs using additive manufacturing required significantly longer fabrication times and higher per-unit expenses than machining, stamping, or injection molding. Equipment and tooling costs combined with material constraints led researchers to reject additive platforms in favor of simpler subtractive or casting alternatives.
Lost to a baseline
High-volume production economics heavily favor conventional injection molding, casting, and stamping over 3D printing due to dramatically lower per-part costs once tooling is amortized
Lost to a baseline
PBF upright printing time (48h/60h total) and cost (1500 €) exceeded conventional machining time (32h/56h total) and cost (1000 €)
Industrialisation of Additive Manufacturing ¿ A Holistic approach: From design to production · IRIS - POLITO - prod
Lost to a baseline
PBF total production time (80h) and printing cost (1600 €) for steering mount exceeded conventional machining/welding time (72h/100h) and cost (1000 €)
Industrialisation of Additive Manufacturing ¿ A Holistic approach: From design to production · IRIS - POLITO - prod
Lost to a baseline
Handcrafted two-part fiberglass molds for shaped precast beams cost significantly less per unit ($8,650 for up to 200 reuses) than 3D printing mass-customized clay bovedillas ($18,900 in labor).
Programmable Mud: 3D Printing earth to achieve low-carbon, low-cost construction automation · MIT
Considered and rejected
Considered and rejected: Additive manufacturing (3D printing) was rejected in favor of CNC subtractive milling of foam board due to cost-effectiveness, durability, and speed.
Assessing understanding gained of Nottingham Caves through Projected Augmented Relief Model (PARM) Developing a strategy to measure the understanding gained of Nottingham Caves through the Projected Augmented Relief Model (PARM) · University of Nottingham Repository
Considered and rejected
Considered and rejected: Rejected 3D printing in favor of laser cutting for mechanical fabrication due to reproducibility, speed, and material availability.
At Least, Be Human: Humanizing the Robot as a Medium for Communication · Cornell
Considered and rejected
Considered and rejected: Rejected CNC milling and metal 3D printing for prototype fin manufacturing due to time and cost constraints, selecting SLA 3D printing instead
Design and Development of Stability and Control Systems for Small, Deployable Aircraft · MIT
Considered and rejected
Considered and rejected: Commercial 3D printing architectures (FDM, SLA, powder bed fusion, binder jet, ink jet, concrete extrusion) were rejected because they require pre-made compatible base materials, add process complexity for polymer-aluminum mixtures, and are expensive (>$1000).
Development of a 3D Printer for Oxide-free Aluminum Transportation · MIT
Considered and rejected
Considered and rejected: Additively manufactured microfeatures via inkjet printing or FDM 3D printing, rejected for general sensor fabrication in favor of the polymer abrading technique due to high hardware complexity, cost, and specialized equipment requirements.
Considered and rejected
Considered and rejected: Rejected Additive Manufacturing (3D printing) for prototype fabrication due to lack of large-scale printer and manual printing instability
Building with Biomaterials · DalSpace
Substrate detachment, component wear, and hardware limitations impair fabrication viability
Extruded filaments detached from flexible textile substrates and caused nozzle blockages due to poor interfacial adhesion and clearance constraints. Hardware failures, abrasive nozzle degradation during metal filament handling, and machine articulation issues further restricted physical manufacturing feasibility.
Tried and failed
toolhead articulation on multi-axis CNC machines applied to multi-axis additive manufacturing. Reason: wire entanglement, lack of gravity compliance, and incompatibility with standard 3D printing firmware
Multi-axis and multi-material additive manufacturing of electrical traces · Imperial
Tried and failed
nanocellulose reinforcement addition applied to cementitious 3D printing mixtures. Outcome: infeasible cost. Reason: High nanomaterial cost and processing footprint drastically increased mixture expenses and global warming potential.
Towards Low-Cost, Low-Carbon Residential Construction 3D Printing · Georgia Tech
Tried and failed
brass and steel extrusion nozzles applied to metal filament additive manufacturing. Reason: abrasive wear increased nozzle exit diameter during heated metal contact
Hybrid extrusion and multidirectional forging additive manufacturing technique · Imperial
Tried and failed
laser powder bed fusion metal additive manufacturing applied to aerodynamic rake probes. Reason: 3D printer hardware failure prevented fabrication of the test article
Tried and failed
bio-filler composites with polymer binders applied to construction 3D printing materials. Outcome: worse than baseline. Reason: Polymeric binders had higher embodied carbon per kilogram than traditional Portland cement.
Towards Low-Cost, Low-Carbon Residential Construction 3D Printing · Georgia Tech
Tried and failed
direct 3D printing with thin layers applied to flexible textile fabric substrates. Reason: filament detached and left gaps under peeling force due to insufficient interfacial adhesion
Revitalization of the embroidery industry using advanced technology in Saudi Arabia · Cranfield
Tried and failed
laser shock peening before post-build annealing applied to additively manufactured gold alloy. Reason: initial tensile-selected variants from printing persisted, preventing expected compressive variant selection during annealing
Understanding Thermomechanical Treatments Induced by Laser Powder Bed Fusion Process · EPFL
Considered and rejected
Considered and rejected: Rejected SLA 3D printing resins (Formlabs Clear, Tough 2000, Rigid 10K, Rigid 4000) for cryogenic low TRo testing due to thermal stress cracking/brittle failure under bending moments, adopting SLS Nylon 12 instead.
High speed film cooling parameters and optimization · UT Austin
Considered and rejected
Considered and rejected: Rejected relying exclusively on physical 3D printed phantoms because current 3D printing materials have a limited range of radiodensity for soft tissue representation
Truth-based Radiomics for Prediction of Lung Cancer Prognosis · DukeSpace
Tried and failed
Thin layer height FDM with flexible polymer applied to direct 3D printing on textiles. Reason: Low layer thickness caused nozzle blocking and poor surface roughness across fabric substrates
Revitalization of the embroidery industry using advanced technology in Saudi Arabia · Cranfield
Cytotoxicity, resin leaching, and chemical contamination hinder biomedical and microfluidic applications
Residual photoinitiators, unreacted monomers, and toxic leachates in photopolymer resins inhibited microbial and cellular growth. In microfluidic and tissue engineering devices, chemical leaching interfered with platinum-catalyzed PDMS crosslinking and failed to support proper cell viability.
Considered and rejected
Considered and rejected: Rejected fuse-deposition modelling (FDM) 3D printing for PEEK device due to culture medium absorption through high material porosity, selecting CNC machining instead
The influence of temporal interference stimulation on neurogenesis in Alzheimer’s disease · Imperial
Tried and failed
photopolymer 3D printing for microfluidic cell culture applied to microbial growth chambers. Reason: resin devices released toxic leachates that inhibited cell growth
Modeling Algal Growth Under Controlled Microenvironment Using a Microfluidic Platform · Cornell
Tried and failed
Casting PDMS in SLA 3D printed molds applied to Microfluidic device fabrication. Reason: Uncured resin components and photoinitiators leach into PDMS and inhibit platinum-catalyzed crosslinking
Design and development of cost-effective and portable 3D printed biomedical equipment · Iowa State
Considered and rejected
Considered and rejected: Solvent-based extrusion and SLA stereolithography for PCL bioscaffolds were rejected due to altered mechanical rigidity, bridging limits, and potential cytotoxicity/crosslinker biocompatibility concerns.
Additive Manufacture of Parametrically Modulated Porous Scaffold Architectures for Medical Device Applications · Research Repository UCD
Considered and rejected
Considered and rejected: Rejected Induracast and Indurasupport / Indurafill printing materials due to high cytotoxicity to cells.
Considered and rejected
Considered and rejected: Rejected stereolithography (SLA) 3D printing in favor of FDM due to toxicity and leaching of unreacted photoinitiators/resins.
A Multifaceted Approach to Preserve Effective Antibiotics Utilizing Antibiotic Susceptibility Testing, Antimicrobial Coatings or Glycomimetic Adjuvants · Publikationssystem UB Tuebingen
Considered and rejected
Considered and rejected: Solely extrusion-printed scaffolds rejected for endothelialization due to large pore sizes (>100 µm), excessive rigidity, and lack of cell adhesion across strands.
Entwicklung geeigneter Strategien für den 3D-Druck von Scaffolds für das Tissue Engineering vaskulärer Strukturen · Leibniz Universität Hannover Repository
Considered and rejected
Considered and rejected: Rejected coupled bioprinting (simultaneous cell and sacrificial material deposition) due to extended hypoxia and fabrication stress accumulation in large tissues
Endothelial Track Patterning for Directing Vascularization of Engineered Tissues · ResearchWorks
Left open by the authors
Problems the authors named and did not get to.
Left open
Redesign the additive manufacturing deposition toolhead with a higher-power extrusion heater to achieve faster extrusion rates. Blocker: Requires specialized additive manufacturing hardware, physical tooling, and laboratory testing facilities
Hybrid extrusion and multidirectional forging additive manufacturing technique · Imperial
Left open
Investigate alternative materials and innovative manufacturing techniques to evaluate mechanical behavior and viability in extrusion additive manufacturing. Blocker: Requires additive manufacturing physical hardware and mechanical testing laboratory equipment
Metodología para la optimización de parámetros geométricos en el proceso de fabricación aditiva basada en extrusión · accedaCRIS
Left open
Compare boiling curves between machined Al 6061 and 3D-printed SLM surfaces to investigate the negative boiling curve slope. Blocker: Requires selective laser melting (SLM) 3D printing, machining of Al 6061, and physical thermal boiling experiment apparatus.
Characterization of Heat Exchange for Additively Manufactured Components · YorkSpace
Left open
Fabricate synthetic trees with 3D-branching xylem pathways using additive manufacturing to optimize hydraulic properties and cavitation mitigation. Blocker: Requires physical additive manufacturing/3D printing fabrication equipment and wet-lab experimental testing of hydraulic and cavitation properties.
Scalable Synthetic Trees for Transpiration-Powered Hydraulic Systems · Virginia Tech
Left open
Investigate polypropylene composites with new combinations of conductive fillers such as graphene nanoplatelets for additive manufacturing. Blocker: Requires materials synthesis, compounding equipment, twin-screw/single-screw extruders, and FDM 3D printing lab facilities.
Additive Manufacturing of Polypropylene Composites with Enhanced Mechanical and Electrical Properties · IRIS - POLITO - prod
Left open
Perform mechanical shear testing on multi-material 3D printed specimens using ASTM D5379, ASTM D3528, or Iosipescu standards to reduce out-of-plane bending. Blocker: Requires multi-material 3D printing equipment (FFF/DLP) and physical mechanical shear testing apparatus (tensile/shear load frames)
Analysis of the Interface Properties of Multi-material 3D Printed Structures · YorkSpace
Left open
Fabricate and test 3D-printed tendon systems using lower elastic moduli materials under external deformations and channel curvatures exceeding 30 degrees. Blocker: Requires a physical fabrication setup (multi-material 3D printing) and experimental testing apparatus for robotic tendon channels.
CONTROLLING STIFFNESS WITH TENDON - FLUID TENSEGRITY · Cornell
Left open
Investigate crack propagation in 3D-printed composite structures subjected to dynamic thermo-mechanical loads. Blocker: Requires additive manufacturing fabrication, material characterization, and dynamic thermo-mechanical physical testing equipment.
Left open
Perform high cycle and low cycle fatigue testing and crack propagation analysis on 3D printed gradient 316L stainless steel specimens. Blocker: Requires selective laser melting 3D printing equipment and physical mechanical/fatigue testing apparatus
3-D Printing, Characterizing and Evaluating the Mechanical Properties of 316L Stainless Steel Materials with Gradient Microstructure · Virginia Tech
Left open
Evaluate dynamic response of specimens fabricated with locally varying 3D printing parameters across individual parts. Blocker: Requires 3D printing hardware and physical dynamic mechanical testing equipment to fabricate and evaluate specimens.
Checking a claim in this area?
We can run the same search on any method or claim. If nothing turns up, we will say so, and that proves nothing on its own.