Publications by authors named "Cem B Dayan"

Considering the characteristics and operating environment of remotely controlled miniature soft robots, achieving delicate adhesion control over various target surfaces is a substantial challenge. In particular, the ability to delicately grasp wrinkled and soft biological and nonbiological surfaces with low preload without causing damage is essential. The proposed adhesive robotic system, inspired by the secretions from a velvet worm, uses a structured magnetorheological material that exhibits precise adhesion control with stability and repeatability by the rapid stiffness change controlled by an external magnetic field.

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High-precision additive manufacturing technologies, such as two-photon polymerization, are mainly limited to photo-curable polymers and currently lacks the possibility to produce multimaterial components. Herein, we report a physically bottom-up assembly strategy that leverages capillary force to trap various nanomaterials and assemble them onto three-dimensional (3D) microscaffolds. This capillary-trapping strategy enables precise and uniform assembly of nanomaterials into versatile 3D microstructures with high uniformity and mass loading.

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Translating medical microrobots into clinics requires tracking, localization, and performing assigned medical tasks at target locations, which can only happen when appropriate design, actuation mechanisms, and medical imaging systems are integrated into a single microrobot. Despite this, these parameters are not fully considered when designing macrophage-based microrobots. This study presents living macrophage-based microrobots that combine macrophages with magnetic Janus particles coated with FePt nanofilm for magnetic steering and medical imaging and bacterial lipopolysaccharides for stimulating macrophages in a tumor-killing state.

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Bioinspired fibrillar structures are promising for a wide range of disruptive adhesive applications. Especially micro/nanofibrillar structures on gecko toes can have strong and controllable adhesion and shear on a wide range of surfaces with residual-free, repeatable, self-cleaning, and other unique features. Synthetic dry fibrillar adhesives inspired by such biological fibrils are optimized in different aspects to increase their performance.

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Article Synopsis
  • Atomic Layer Deposition (ALD) provides a high-quality, conformal coating ideal for protecting sensitive materials, but optimizing the deposition parameters is complex due to the high number of variables involved.
  • Machine-learning methods, particularly Bayesian optimization (BO), have proven effective at minimizing defects in an ALD-AlO passivation layer for corrosion protection of copper, achieving optimal results in fewer than three trials.
  • The study shows that with the optimized parameters, including surface pretreatment and specific deposition conditions, the corrosion resistance is significantly improved, highlighting the potential of integrating machine learning in materials science.
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Bioinspired elastomeric structural adhesives can provide reversible and controllable adhesion on dry/wet and synthetic/biological surfaces for a broad range of commercial applications. Shape complexity and performance of the existing structural adhesives are limited by the used specific fabrication technique, such as molding. To overcome these limitations by proposing complex 3D microstructured adhesive designs, a 3D elastomeric microstructure fabrication approach is implemented using two-photon-polymerization-based 3D printing.

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Gecko adhesive performance increases as relative humidity increases. Two primary mechanisms can explain this result: capillary adhesion and increased contact area via material softening. Both hypotheses consider variable relative humidity, but neither fully explains the interactive effects of temperature and relative humidity on live gecko adhesion.

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To explore novel materials graded for biological functions is one of the grand challenges and ambitions of robotics. In this study, the design, development, and external guidance of micron-sized hair-derived robots (hairbots) are shown as autologous cargo carriers for guided drug delivery, untethered osteogenesis, and sonographic contrast agents. Having biogenic origin, the hairbots show excellent biocompatibility, as demonstrated with cell adhesion, spreading and proliferation.

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