Abstract A primary challenge in the field of reconfigurable robotics is scaling down the size of ... more Abstract A primary challenge in the field of reconfigurable robotics is scaling down the size of individual robotic modules. We present a novel set of permanent magnet modules that are under 1 mm in all dimensions, called Mag-µMods, for use in a reconfigurable micro-system. The modules are actuated by oscillating external magnetic fields of several mT in strength, and are capable of locomoting on a 2-D surface.
Abstract This paper presents the fabrication, characterization and testing of bio-inspired synthe... more Abstract This paper presents the fabrication, characterization and testing of bio-inspired synthetic dry adhesive fiber arrays. Fibers were fabricated via micromolding followed by spatula tip formation via dipping. Arrays of fibers with diameters between 28 mum and 57 mum and a height of 114 mum were fabricated with high uniformity on 6.25 cm 2 areas with up to 95% yield. Adaptation to uneven surfaces was observed with fiber elongations over 6 times the original height of the fiber.
Abstract Optical tweezers have been used as versatile tools for non-contact manipulation of micro... more Abstract Optical tweezers have been used as versatile tools for non-contact manipulation of micrometer-sized particles. This paper proposes a hybrid micro/nanoscale manufacturing system using optical tweezers and chemical linkages for fabricating 2D and 3D micro/nanostructures. A holographic multiple trap optical tweezer system is first used to trap particles in a desired pattern. The particles are then connected to form rigid units using suitable chemistry.
Abstract In this paper, manipulation systems from a macroscale world to nanoscale world which are... more Abstract In this paper, manipulation systems from a macroscale world to nanoscale world which are indispensable for constructing nanoelectromechanical systems are introduced, and a macro to nano telemanipulation system has been proposed. We selected the tele-robotics manipulation approach for positioning nano objects with sizes between 1 nm and 10 μm in 2-D. A user interface enables the operator to feel the nano forces using a haptic device and see the 3-D graphics of the nano world during the manipulation.
Abstract A nano-robotic manipulation system using an atomic force microscope probe as the pushing... more Abstract A nano-robotic manipulation system using an atomic force microscope probe as the pushing manipulator and force and topology sensor is proposed. The task is the two-dimensional positioning of nanometer-size particles on a substrate in ambient conditions. Thus, the modeling of interaction forces and dynamics during the pushing operation is analyzed, and compared with the experimental results for an improved understanding of the nano scale physical phenomenon which is different from macro scale physics.
Angled polyurethane fiber arrays are modified by adding soft spherical and spatula shaped tips vi... more Angled polyurethane fiber arrays are modified by adding soft spherical and spatula shaped tips via dipping. These fibers are characterized for adhesion and friction and compared with unmodified fibers and flat material samples. Sphere and spatula tip fiber samples demonstrate increased adhesion, with 10 and 23 times the maximum adhesion of the unmodified fiber sample, respectively.
Abstract In this paper, the design, analysis, and fabrication of a gecko-inspired climbing robot ... more Abstract In this paper, the design, analysis, and fabrication of a gecko-inspired climbing robot are discussed. The robot has kinematics similar to a gecko's climbing gait. It uses peeling and steering mechanisms and an active tail for robust and agile climbing as a novelty. The advantage of this legged robot is that it can explore irregular terrains more robustly. Novel peeling mechanism of the elastomer adhesive pads, as well as steering and stable climbing using an active tail are explored.
Abstract This paper proposes two different nanomolding methods to fabricate synthetic gecko foot-... more Abstract This paper proposes two different nanomolding methods to fabricate synthetic gecko foot-hair nanostructures. The first method uses an atomic force microscope (AFM) probe indented flat wax surface and the second one uses a nano-pore membrane as a template. These templates are molded with silicone rubber, polyimide and polyester type polymers under vacuum and the template is peeled off or etched away.
Abstract Recent biological studies on water strider insects revealed how they maintain stability ... more Abstract Recent biological studies on water strider insects revealed how they maintain stability and maneuver on the surface of water. While macroscale bodies use buoyancy, these very small insects use surface tension force to balance their weight on water. This paper proposes a biologically inspired miniature robot that utilizes the unique scaling advantage of these insects.
Abstract The effect of aspect ratio on the pull-off stress and stiffness of soft elastic fibres i... more Abstract The effect of aspect ratio on the pull-off stress and stiffness of soft elastic fibres is studied using elasticity and numerical analysis. The adhesive interface between a soft fibre and a smooth rigid surface is modelled using the Dugdale–Barenblatt model. Numerical simulations show that, while pull-off stress increases with decreasing aspect ratio, fibres get stiffer. Also, for sufficiently low aspect ratio fibres, failure occurs via the growth of internal cracks and pull-off stress approaches the intrinsic adhesive strength.
In this paper, a visual and haptic human–machine interface is proposed for teleoperated nano-scal... more In this paper, a visual and haptic human–machine interface is proposed for teleoperated nano-scale object interaction and manipulation. Design specifications for a bilateral scaled tele-operation system with slave and master robots, sensors, actuators and control are discussed. The Phantom™ haptic device is utilized as the master manipulator, and a piezoresistive atomic force microscope probe is selected as the slave manipulator and as topography and force sensors.
Abstract Vertically aligned carbon nanofibers partially embedded inside polyurethane (eVACNFs) ar... more Abstract Vertically aligned carbon nanofibers partially embedded inside polyurethane (eVACNFs) are proposed as a robust high friction fibrillar material with a compliant backing. Carbon nanofibers with 50–150 nm in diameter and 20–30 μm in length are vertically grown on silicon and transferred completely inside an elastomer by vacuum molding. By using time controlled and selective oxygen plasma etching, fibers are partially released up to 5 μm length.
Abstract A micro-pillar-based silicone rubber adhesive coated with a thin silicone oil layer is i... more Abstract A micro-pillar-based silicone rubber adhesive coated with a thin silicone oil layer is investigated in this paper for developing friction-based clamping mechanisms for robotic endoscopic microcapsules. These adhesives are shown to enhance the frictional force between the capsule and the intestinal wall by a factor of about seven over a non-patterned flat elastomer material. In this study, tests performed on fresh samples of pig small intestine are used to optimize the diameter of the micro-pillars to maximize the frictional forces.
Abstract This work presents an untethered magnetic micro-robot with dimensions of 250 mum x 130 m... more Abstract This work presents an untethered magnetic micro-robot with dimensions of 250 mum x 130 mum x 100 mum. The robot is composed entirely of neodymium-iron-boron fabricated using laser micro-machining. It is actuated by a system of five macro-scale electromagnets. By using electromagnets to control the robot, the surface on which the robot operates need not be specialized, smooth, patterned, nor conductive. Two control methods, both based on periodic excitation of the robot, are attempted and compared.
Abstract This paper proposes a nanorobotic fiber fabrication method which uses proximal probes to... more Abstract This paper proposes a nanorobotic fiber fabrication method which uses proximal probes to draw polymer fibers down to few hundred nanometers in diameter and several hundred micrometers in length. Using proximal probes such as Atomic Force Microscope (AFM) and Scanning Tunneling Microscope (STM) or glass micropipettes, liquid polymers dissolved in a solvent are drawn. During drawing, the solvent evaporates in real-time which solidifies the fiber.
Abstract Previous studies have demonstrated that gecko foot-hair inspired elastomer microfibers w... more Abstract Previous studies have demonstrated that gecko foot-hair inspired elastomer microfibers with spatulate tips have significant adhesion enhancement compared to the flat elastomer surface. In this study, we report the friction enhancement of these highly adhesive fibers and analyze the relation between adhesion and friction of elastomer microfiber arrays with spatulate tips.
Abstract A recent experiment has shown that the force required to pull off a flat circular rigid ... more Abstract A recent experiment has shown that the force required to pull off a flat circular rigid punch in adhesive contact with an array of elastic fibrils is sensitive to the thickness of the elastic backing layer to which these fibrils are attached. This result motivates us to study the effect of sample compliance on the adhesion of fibril arrays. A closed form expression for the compliance of such arrays attached to a backing layer of finite thickness is derived. Our model is based on the assumption that the adhesive strength of a fibril is deterministic.
Abstract A telemanipulation system from macroscale world to nanoscale world with a user-friendly ... more Abstract A telemanipulation system from macroscale world to nanoscale world with a user-friendly virtual reality-based human-machine interface has been proposed in this paper. This paper focuses on the direct telemanipulation of nano objects with sizes 1 nm-1 μm. A home-made AFM device has been utilized as the nano vision and force sensor as well as the nano manipulator. As the teleoperation interface, a force-feedback device and 3-D virtual reality graphics visualization environment have been constructed.
Abstract: Autonomous micromanipulation has been an emerging interest in constructing and assembli... more Abstract: Autonomous micromanipulation has been an emerging interest in constructing and assembling micro-objects. Manual assembly and manipulation of small-scale objects through teleoperation is possible; however, autonomy is necessary for large-volume manipulation and manufacturing. In this study, we discuss a two-dimensional autonomous manipulation system, which is based on an optical microscope and a nanoprobe.
Abstract In this paper, the design, analysis, and development of a sixteen-legged palm-sized clim... more Abstract In this paper, the design, analysis, and development of a sixteen-legged palm-sized climbing robot using flat bulk tacky elastomer adhesives as an attachment method is presented. A legged robot with four-bar based kinematics is designed and fabricated with elastomeric footpads. The proposed robot has a passive peeling mechanism for energy efficient and vibration free detachment.
Abstract A primary challenge in the field of reconfigurable robotics is scaling down the size of ... more Abstract A primary challenge in the field of reconfigurable robotics is scaling down the size of individual robotic modules. We present a novel set of permanent magnet modules that are under 1 mm in all dimensions, called Mag-µMods, for use in a reconfigurable micro-system. The modules are actuated by oscillating external magnetic fields of several mT in strength, and are capable of locomoting on a 2-D surface.
Abstract This paper presents the fabrication, characterization and testing of bio-inspired synthe... more Abstract This paper presents the fabrication, characterization and testing of bio-inspired synthetic dry adhesive fiber arrays. Fibers were fabricated via micromolding followed by spatula tip formation via dipping. Arrays of fibers with diameters between 28 mum and 57 mum and a height of 114 mum were fabricated with high uniformity on 6.25 cm 2 areas with up to 95% yield. Adaptation to uneven surfaces was observed with fiber elongations over 6 times the original height of the fiber.
Abstract Optical tweezers have been used as versatile tools for non-contact manipulation of micro... more Abstract Optical tweezers have been used as versatile tools for non-contact manipulation of micrometer-sized particles. This paper proposes a hybrid micro/nanoscale manufacturing system using optical tweezers and chemical linkages for fabricating 2D and 3D micro/nanostructures. A holographic multiple trap optical tweezer system is first used to trap particles in a desired pattern. The particles are then connected to form rigid units using suitable chemistry.
Abstract In this paper, manipulation systems from a macroscale world to nanoscale world which are... more Abstract In this paper, manipulation systems from a macroscale world to nanoscale world which are indispensable for constructing nanoelectromechanical systems are introduced, and a macro to nano telemanipulation system has been proposed. We selected the tele-robotics manipulation approach for positioning nano objects with sizes between 1 nm and 10 μm in 2-D. A user interface enables the operator to feel the nano forces using a haptic device and see the 3-D graphics of the nano world during the manipulation.
Abstract A nano-robotic manipulation system using an atomic force microscope probe as the pushing... more Abstract A nano-robotic manipulation system using an atomic force microscope probe as the pushing manipulator and force and topology sensor is proposed. The task is the two-dimensional positioning of nanometer-size particles on a substrate in ambient conditions. Thus, the modeling of interaction forces and dynamics during the pushing operation is analyzed, and compared with the experimental results for an improved understanding of the nano scale physical phenomenon which is different from macro scale physics.
Angled polyurethane fiber arrays are modified by adding soft spherical and spatula shaped tips vi... more Angled polyurethane fiber arrays are modified by adding soft spherical and spatula shaped tips via dipping. These fibers are characterized for adhesion and friction and compared with unmodified fibers and flat material samples. Sphere and spatula tip fiber samples demonstrate increased adhesion, with 10 and 23 times the maximum adhesion of the unmodified fiber sample, respectively.
Abstract In this paper, the design, analysis, and fabrication of a gecko-inspired climbing robot ... more Abstract In this paper, the design, analysis, and fabrication of a gecko-inspired climbing robot are discussed. The robot has kinematics similar to a gecko's climbing gait. It uses peeling and steering mechanisms and an active tail for robust and agile climbing as a novelty. The advantage of this legged robot is that it can explore irregular terrains more robustly. Novel peeling mechanism of the elastomer adhesive pads, as well as steering and stable climbing using an active tail are explored.
Abstract This paper proposes two different nanomolding methods to fabricate synthetic gecko foot-... more Abstract This paper proposes two different nanomolding methods to fabricate synthetic gecko foot-hair nanostructures. The first method uses an atomic force microscope (AFM) probe indented flat wax surface and the second one uses a nano-pore membrane as a template. These templates are molded with silicone rubber, polyimide and polyester type polymers under vacuum and the template is peeled off or etched away.
Abstract Recent biological studies on water strider insects revealed how they maintain stability ... more Abstract Recent biological studies on water strider insects revealed how they maintain stability and maneuver on the surface of water. While macroscale bodies use buoyancy, these very small insects use surface tension force to balance their weight on water. This paper proposes a biologically inspired miniature robot that utilizes the unique scaling advantage of these insects.
Abstract The effect of aspect ratio on the pull-off stress and stiffness of soft elastic fibres i... more Abstract The effect of aspect ratio on the pull-off stress and stiffness of soft elastic fibres is studied using elasticity and numerical analysis. The adhesive interface between a soft fibre and a smooth rigid surface is modelled using the Dugdale–Barenblatt model. Numerical simulations show that, while pull-off stress increases with decreasing aspect ratio, fibres get stiffer. Also, for sufficiently low aspect ratio fibres, failure occurs via the growth of internal cracks and pull-off stress approaches the intrinsic adhesive strength.
In this paper, a visual and haptic human–machine interface is proposed for teleoperated nano-scal... more In this paper, a visual and haptic human–machine interface is proposed for teleoperated nano-scale object interaction and manipulation. Design specifications for a bilateral scaled tele-operation system with slave and master robots, sensors, actuators and control are discussed. The Phantom™ haptic device is utilized as the master manipulator, and a piezoresistive atomic force microscope probe is selected as the slave manipulator and as topography and force sensors.
Abstract Vertically aligned carbon nanofibers partially embedded inside polyurethane (eVACNFs) ar... more Abstract Vertically aligned carbon nanofibers partially embedded inside polyurethane (eVACNFs) are proposed as a robust high friction fibrillar material with a compliant backing. Carbon nanofibers with 50–150 nm in diameter and 20–30 μm in length are vertically grown on silicon and transferred completely inside an elastomer by vacuum molding. By using time controlled and selective oxygen plasma etching, fibers are partially released up to 5 μm length.
Abstract A micro-pillar-based silicone rubber adhesive coated with a thin silicone oil layer is i... more Abstract A micro-pillar-based silicone rubber adhesive coated with a thin silicone oil layer is investigated in this paper for developing friction-based clamping mechanisms for robotic endoscopic microcapsules. These adhesives are shown to enhance the frictional force between the capsule and the intestinal wall by a factor of about seven over a non-patterned flat elastomer material. In this study, tests performed on fresh samples of pig small intestine are used to optimize the diameter of the micro-pillars to maximize the frictional forces.
Abstract This work presents an untethered magnetic micro-robot with dimensions of 250 mum x 130 m... more Abstract This work presents an untethered magnetic micro-robot with dimensions of 250 mum x 130 mum x 100 mum. The robot is composed entirely of neodymium-iron-boron fabricated using laser micro-machining. It is actuated by a system of five macro-scale electromagnets. By using electromagnets to control the robot, the surface on which the robot operates need not be specialized, smooth, patterned, nor conductive. Two control methods, both based on periodic excitation of the robot, are attempted and compared.
Abstract This paper proposes a nanorobotic fiber fabrication method which uses proximal probes to... more Abstract This paper proposes a nanorobotic fiber fabrication method which uses proximal probes to draw polymer fibers down to few hundred nanometers in diameter and several hundred micrometers in length. Using proximal probes such as Atomic Force Microscope (AFM) and Scanning Tunneling Microscope (STM) or glass micropipettes, liquid polymers dissolved in a solvent are drawn. During drawing, the solvent evaporates in real-time which solidifies the fiber.
Abstract Previous studies have demonstrated that gecko foot-hair inspired elastomer microfibers w... more Abstract Previous studies have demonstrated that gecko foot-hair inspired elastomer microfibers with spatulate tips have significant adhesion enhancement compared to the flat elastomer surface. In this study, we report the friction enhancement of these highly adhesive fibers and analyze the relation between adhesion and friction of elastomer microfiber arrays with spatulate tips.
Abstract A recent experiment has shown that the force required to pull off a flat circular rigid ... more Abstract A recent experiment has shown that the force required to pull off a flat circular rigid punch in adhesive contact with an array of elastic fibrils is sensitive to the thickness of the elastic backing layer to which these fibrils are attached. This result motivates us to study the effect of sample compliance on the adhesion of fibril arrays. A closed form expression for the compliance of such arrays attached to a backing layer of finite thickness is derived. Our model is based on the assumption that the adhesive strength of a fibril is deterministic.
Abstract A telemanipulation system from macroscale world to nanoscale world with a user-friendly ... more Abstract A telemanipulation system from macroscale world to nanoscale world with a user-friendly virtual reality-based human-machine interface has been proposed in this paper. This paper focuses on the direct telemanipulation of nano objects with sizes 1 nm-1 μm. A home-made AFM device has been utilized as the nano vision and force sensor as well as the nano manipulator. As the teleoperation interface, a force-feedback device and 3-D virtual reality graphics visualization environment have been constructed.
Abstract: Autonomous micromanipulation has been an emerging interest in constructing and assembli... more Abstract: Autonomous micromanipulation has been an emerging interest in constructing and assembling micro-objects. Manual assembly and manipulation of small-scale objects through teleoperation is possible; however, autonomy is necessary for large-volume manipulation and manufacturing. In this study, we discuss a two-dimensional autonomous manipulation system, which is based on an optical microscope and a nanoprobe.
Abstract In this paper, the design, analysis, and development of a sixteen-legged palm-sized clim... more Abstract In this paper, the design, analysis, and development of a sixteen-legged palm-sized climbing robot using flat bulk tacky elastomer adhesives as an attachment method is presented. A legged robot with four-bar based kinematics is designed and fabricated with elastomeric footpads. The proposed robot has a passive peeling mechanism for energy efficient and vibration free detachment.
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Papers by Metin Sitti