Publications | Max Planck Institute for Intelligent Systems

38 results (View BibTeX file of all listed publications)

2016

Bioengineered and biohybrid bacteria-based systems for drug delivery

Hosseinidoust, Z., Mostaghaci, B., Yasa, O., Park, B., Singh, A. V., Sitti, M.

Advanced Drug Delivery Reviews, 106, pages: 27-44, Elsevier, November 2016 (article)

Abstract

The use of bacterial cells as agents of medical therapy has a long history. Research that was ignited over a century ago with the accidental infection of cancer patients has matured into a platform technology that offers the promise of opening up new potential frontiers in medical treatment. Bacterial cells exhibit unique characteristics that make them well-suited as smart drug delivery agents. Our ability to genetically manipulate the molecular machinery of these cells enables the customization of their therapeutic action as well as its precise tuning and spatio-temporal control, allowing for the design of unique, complex therapeutic functions, unmatched by current drug delivery systems. Early results have been promising, but there are still many important challenges that must be addressed. We present a review of promises and challenges of employing bioengineered bacteria in drug delivery systems and introduce the biohybrid design concept as a new additional paradigm in bacteria-based drug delivery.

DOI Project Page [BibTex]

2016

pi Hosseinidoust, Z., Mostaghaci, B., Yasa, O., Park, B., Singh, A. V., Sitti, M. Bioengineered and biohybrid bacteria-based systems for drug delivery Advanced Drug Delivery Reviews, 106, pages: 27-44, Elsevier, November 2016 (article)

DOI Project Page [BibTex]

A 5-D localization method for a magnetically manipulated untethered robot using a 2-D array of Hall-effect sensors

Son, D., Yim, S., Sitti, M.

IEEE/ASME Transactions on Mechatronics, 21(2):708-716, IEEE, October 2016 (article)

Abstract

This paper introduces a new five-dimensional localization method for an untethered meso-scale magnetic robot, which is manipulated by a computer-controlled electromagnetic system. The developed magnetic localization setup is a two-dimensional array of mono-axial Hall-effect sensors, which measure the perpendicular magnetic fields at their given positions. We introduce two steps for localizing a magnetic robot more accurately. First, the dipole modeled magnetic field of the electromagnet is subtracted from the measured data in order to determine the robot's magnetic field. Secondly, the subtracted magnetic field is twice differentiated in the perpendicular direction of the array, so that the effect of the electromagnetic field in the localization process is minimized. Five variables regarding the position and orientation of the robot are determined by minimizing the error between the measured magnetic field and the modeled magnetic field in an optimization method. The resulting position error is 2.1±0.8 mm and angular error is 6.7±4.3° within the applicable range (5 cm) of magnetic field sensors at 200 Hz. The proposed localization method would be used for the position feedback control of untethered magnetic devices or robots for medical applications in the future.

DOI Project Page [BibTex]

pi Son, D., Yim, S., Sitti, M. A 5-D localization method for a magnetically manipulated untethered robot using a 2-D array of Hall-effect sensors IEEE/ASME Transactions on Mechatronics, 21(2):708-716, IEEE, October 2016 (article)

DOI Project Page [BibTex]

High-Performance Multiresponsive Paper Actuators

Amjadi, M., Sitti, M.

ACS Nano, 10(11):10202-10210, American Chemical Society, October 2016 (article)

Abstract

There is an increasing demand for soft actuators because of their importance in soft robotics, artificial muscles, biomimetic devices, and beyond. However, the development of soft actuators capable of low-voltage operation, powerful actuation, and programmable shape-changing is still challenging. In this work, we propose programmable bilayer actuators that operate based on the large hygroscopic contraction of the copy paper and simultaneously large thermal expansion of the polypropylene film upon increasing the temperature. The electrothermally activated bending actuators can function with low voltages (≤ 8 V), low input electric power per area (P ≤ 0.14 W cm–2), and low temperature changes (≤ 35 °C). They exhibit reversible shape-changing behavior with curvature radii up to 1.07 cm–1 and bending angle of 360°, accompanied by powerful actuation. Besides the electrical activation, they can be powered by humidity or light irradiation. We finally demonstrate the use of our paper actuators as a soft gripper robot and a lightweight paper wing for aerial robotics.

DOI Project Page Project Page [BibTex]

pi Amjadi, M., Sitti, M. High-Performance Multiresponsive Paper Actuators ACS Nano, 10(11):10202-10210, American Chemical Society, October 2016 (article)

DOI Project Page Project Page [BibTex]

Programmable assembly of heterogeneous microparts by an untethered mobile capillary microgripper

Giltinan, J., Diller, E., Sitti, M.

Lab on a Chip, 16(22):4445-4457, Royal Society of Chemistry, October 2016 (article)

Abstract

At the sub-millimeter scale, capillary forces enable robust and reversible adhesion between biological organisms and varied substrates. Current human-engineered mobile untethered micromanipulation systems rely on forces which scale poorly or utilize gripper-part designs that promote manipulation. Capillary forces, alternatively, are dependent upon the surface chemistry (which is scale independent) and contact perimeter, which conforms to the part surface. We report a mobile capillary microgripper that is able to pick and place parts of various materials and geometries, and is thus ideal for microassembly tasks that cannot be accomplished by large tethered manipulators. We achieve the programmable assembly of sub-millimeter parts in an enclosed three-dimensional aqueous environment by creating a capillary bridge between the targeted part and a synthetic, untethered, mobile body. The parts include both hydrophilic and hydrophobic components: hydrogel, kapton, human hair, and biological tissue. The 200 μm untethered system can be controlled with five-degrees-of-freedom and advances progress towards autonomous desktop manufacturing for tissue engineering, complex micromachines, microfluidic devices, and meta-materials.

DOI Project Page [BibTex]

pi Giltinan, J., Diller, E., Sitti, M. Programmable assembly of heterogeneous microparts by an untethered mobile capillary microgripper Lab on a Chip, 16(22):4445-4457, Royal Society of Chemistry, October 2016 (article)

DOI Project Page [BibTex]

Composition-dependent underwater adhesion of catechol-bearing hydrogels

Wu, H., Sariola, V., Zhao, J., Ding, H., Sitti, M., Bettinger, C. J.

Polymer International, 65(11):1355-1359, John Wiley & Sons, Ltd, September 2016 (article)

Abstract

Interfacial adhesion-mediated transfer printing processes can integrate functional electronic microstructures with polymeric substrates that are bendable and stretchable. Transfer printing has also been extended to catechol-bearing adhesive hydrogels. This study presents indentation adhesion tests between catechol-bearing hydrogel substrates with catechol concentrations varying from 0 to 10% (mol/mol) and thin-film materials commonly used in microelectronic fabrication including polymers, noble metals and oxides. The results indicate that the interfacial adhesion of catechol-bearing hydrogels is positively correlated with the concentration of catechol-bearing monomers as well as the retraction velocity during transfer printing. This study can inform transfer printing processes for microfabricated structures to compliant hydrated substrates such as hygroscopic monomers, mesoporous polymer networks and hydrogels. © 2016 Society of Chemical Industry

DOI [BibTex]

pi Wu, H., Sariola, V., Zhao, J., Ding, H., Sitti, M., Bettinger, C. J. Composition-dependent underwater adhesion of catechol-bearing hydrogels Polymer International, 65(11):1355-1359, John Wiley & Sons, Ltd, September 2016 (article)

DOI [BibTex]

Bacteria-Driven Particles: Patterned and Specific Attachment of Bacteria on Biohybrid Bacteria-Driven Microswimmers (Adv. Healthcare Mater. 18/2016)

Singh, A. V., Sitti, M.

Advanced Healthcare Materials, 5(18):2306-2306, September 2016 (article)

Abstract

On page 2325, Ajay Vikram Singh and Metin Sitti propose a facile surface patterning technique and a specific, strong biotin–streptavidin bonding of bacteria on patterned surfaces to fabricate Janus particles that are propelled by the attached bacteria. Such bacteria-driven Janus microswimmers could be used for future medicine in targeted drug delivery and environmental remediation.

DOI Project Page [BibTex]

pi Singh, A. V., Sitti, M. Bacteria-Driven Particles: Patterned and Specific Attachment of Bacteria on Biohybrid Bacteria-Driven Microswimmers (Adv. Healthcare Mater. 18/2016) Advanced Healthcare Materials, 5(18):2306-2306, September 2016 (article)

DOI Project Page [BibTex]

The effect of temperature and humidity on adhesion of a gecko-inspired adhesive: implications for the natural system

Stark, A. Y., Klittich, M. R., Sitti, M., Niewiarowski, P. H., Dhinojwala, A.

Scientific Reports, 6, pages: 30936, Nature Publishing Group, August 2016 (article)

Abstract

The adhesive system of geckos has inspired hundreds of synthetic adhesives. While this system has been used relentlessly as a source of inspiration, less work has been done in reverse, where synthetics are used to test questions and hypotheses about the natural system. Here we take such an approach. We tested shear adhesion of a mushroom-tipped synthetic gecko adhesive under conditions that produced perplexing results in the natural adhesive system. Synthetic samples were tested at two temperatures (12 °C and 32 °C) and four different humidity levels (30%, 55%, 70%, and 80% RH). Surprisingly, adhesive performance of the synthetic samples matched that of living geckos, suggesting that uncontrolled parameters in the natural system, such as surface chemistry and material changes, may not be as influential in whole-animal performance as previously thought. There was one difference, however, when comparing natural and synthetic adhesive performance. At 12 °C and 80% RH, adhesion of the synthetic structures was lower than expected based on the natural system’s performance. Our approach highlights a unique opportunity for both biologists and material scientists, where new questions and hypotheses can be fueled by joint comparisons of the natural and synthetic systems, ultimately improving knowledge of both.

DOI [BibTex]

pi Stark, A. Y., Klittich, M. R., Sitti, M., Niewiarowski, P. H., Dhinojwala, A. The effect of temperature and humidity on adhesion of a gecko-inspired adhesive: implications for the natural system Scientific Reports, 6, pages: 30936, Nature Publishing Group, August 2016 (article)

DOI [BibTex]

Magnetic propulsion of robotic sperms at low-Reynolds number

Khalil, I. S., Fatih Tabak, A., Klingner, A., Sitti, M.

Applied Physics Letters, 109(3):033701, AIP Publishing, July 2016 (article)

Abstract

We investigate the microswimming behaviour of robotic sperms in viscous fluids. These robotic sperms are fabricated from polystyrene dissolved in dimethyl formamide and iron-oxide nanoparticles. This composition allows the nanoparticles to be concentrated within the bead of the robotic sperm and provide magnetic dipole, whereas the flexibility of the ultra-thin tail enables flagellated locomotion using magnetic fields in millitesla range. We show that these robotic sperms have similar morphology and swimming behaviour to those of sperm cells. Moreover, we show experimentally that our robotic sperms swim controllably at an average speed of approximately one body length per second (around 125 μm s−1), and they are relatively faster than the microswimmers that depend on planar wave propulsion in low-Reynolds number fluids.

DOI [BibTex]

pi Khalil, I. S., Fatih Tabak, A., Klingner, A., Sitti, M. Magnetic propulsion of robotic sperms at low-Reynolds number Applied Physics Letters, 109(3):033701, AIP Publishing, July 2016 (article)

DOI [BibTex]

Six-degree-of-freedom magnetic actuation for wireless microrobotics

Diller, E., Giltinan, J., Lum, G. Z., Ye, Z., Sitti, M.

The International Journal of Robotics Research, 35(1-3):114-128, SAGE Publications Sage UK: London, England, June 2016 (article)

Abstract

Existing remotely actuated magnetic microrobots exhibit a maximum of only five-degree-of-freedom (DOF) actuation, as creation of a driving torque about the microrobot magnetization axis is not achievable. This lack of full orientation control limits the effectiveness of existing microrobots for precision tasks of object manipulation and orientation for advanced medical, biological and micromanufacturing applications. This paper presents a magnetic actuation method that allows remotely powered microrobots to achieve full six-DOF actuation by considering the case of a non-uniform magnetization profile within the microrobot body. This non-uniform magnetization allows for additional rigid-body torques to be induced from magnetic forces via a moment arm. A general analytical model presents the working principle for continuous and discrete magnetization profiles, which is applied to permanent or non-permanent (soft) magnet bodies. Several discrete-magnetization designs are also presented which possess reduced coupling between magnetic forces and induced rigid-body torques. Design guidelines are introduced which can be followed to ensure that a magnetic microrobot design is capable of six-DOF actuation. A simple permanent-magnet prototype is fabricated and used to quantitatively demonstrate the accuracy of the analytical model in a constrained-DOF environment and qualitatively for free motion in a viscous liquid three-dimensional environment. Results show that desired forces and torques can be created with high precision and limited parasitic actuation, allowing for full six-DOF actuation using limited feedback control

DOI [BibTex]

pi Diller, E., Giltinan, J., Lum, G. Z., Ye, Z., Sitti, M. Six-degree-of-freedom magnetic actuation for wireless microrobotics The International Journal of Robotics Research, 35(1-3):114-128, SAGE Publications Sage UK: London, England, June 2016 (article)

DOI [BibTex]

Gallium Adhesion: Phase Change of Gallium Enables Highly Reversible and Switchable Adhesion (Adv. Mater. 25/2016)

Ye, Z., Lum, G. Z., Song, S., Rich, S., Sitti, M.

Advanced Materials, 28(25):5087-5087, May 2016 (article)

Abstract

Gallium exhibits highly reversible and switchable adhesion when it undergoes a solid–liquid phase transition. The robustness of gallium is notable as it exhibits strong performance on a wide range of smooth and rough surfaces, under both dry and wet conditions. Gallium may therefore find numerous applications in transfer printing, robotics, electronic packaging, and biomedicine.

DOI [BibTex]

pi Ye, Z., Lum, G. Z., Song, S., Rich, S., Sitti, M. Gallium Adhesion: Phase Change of Gallium Enables Highly Reversible and Switchable Adhesion (Adv. Mater. 25/2016) Advanced Materials, 28(25):5087-5087, May 2016 (article)

DOI [BibTex]

Patterned and Specific Attachment of Bacteria on Biohybrid Bacteria-Driven Microswimmers

Singh, A. V., Sitti, M.

Advanced Healthcare Materials, 5(18):2325-2331, May 2016 (article)

Abstract

A surface patterning technique and a specific and strong biotin–streptavidin bonding of bacteria on patterned surfaces are proposed to fabricate Janus particles that are propelled by the attached bacteria. Bacteria-driven Janus microswimmers with diameters larger than 3 μm show enhanced mean propulsion speed. Such microswimmers could be used for future applications such as targeted drug delivery and environmental remediation.

DOI [BibTex]

pi Singh, A. V., Sitti, M. Patterned and Specific Attachment of Bacteria on Biohybrid Bacteria-Driven Microswimmers Advanced Healthcare Materials, 5(18):2325-2331, May 2016 (article)

DOI [BibTex]

Shape-programmable magnetic soft matter

Lum, G. Z., Ye, Z., Dong, X., Marvi, H., Erin, O., Hu, W., Sitti, M.

Proceedings of the National Academy of Sciences, 113(41):E6007–E6015, National Acad Sciences, May 2016 (article)

Abstract

Shape-programmable matter is a class of active materials whose geometry can be controlled to potentially achieve mechanical functionalities beyond those of traditional machines. Among these materials, magnetically actuated matter is particularly promising for achieving complex time-varying shapes at small scale (overall dimensions smaller than 1 cm). However, previous work can only program these materials for limited applications, as they rely solely on human intuition to approximate the required magnetization profile and actuating magnetic fields for their materials. Here, we propose a universal programming methodology that can automatically generate the required magnetization profile and actuating fields for soft matter to achieve new time-varying shapes. The universality of the proposed method can therefore inspire a vast number of miniature soft devices that are critical in robotics, smart engineering surfaces and materials, and biomedical devices. Our proposed method includes theoretical formulations, computational strategies, and fabrication procedures for programming magnetic soft matter. The presented theory and computational method are universal for programming 2D or 3D time-varying shapes, whereas the fabrication technique is generic only for creating planar beams. Based on the proposed programming method, we created a jellyfish-like robot, a spermatozoid-like undulating swimmer, and an artificial cilium that could mimic the complex beating patterns of its biological counterpart.

DOI [BibTex]

pi Lum, G. Z., Ye, Z., Dong, X., Marvi, H., Erin, O., Hu, W., Sitti, M. Shape-programmable magnetic soft matter Proceedings of the National Academy of Sciences, 113(41):E6007–E6015, National Acad Sciences, May 2016 (article)

DOI [BibTex]

Inflated soft actuators with reversible stable deformations

Hines, L., Petersen, K., Sitti, M.

Advanced Materials, 28(19):3690-3696, March 2016 (article)

Abstract

Most soft robotic systems are currently dependent on bulky compressors or pumps. A soft actuation method is presented combining hyperelastic membranes and dielectric elastomer actuators to switch between stable deformations of sealed chambers. This method is capable of large repeatable deformations, and has a number of stable states proportional to the number of actuatable membranes in the chamber.

DOI Project Page [BibTex]

pi Hines, L., Petersen, K., Sitti, M. Inflated soft actuators with reversible stable deformations Advanced Materials, 28(19):3690-3696, March 2016 (article)

DOI Project Page [BibTex]

Chemotaxis of bio-hybrid multiple bacteria-driven microswimmers

Zhuang, J., Sitti, M.

Scientific reports, 6, pages: 32135, Nature Publishing Group, March 2016 (article)

Abstract

In this study, in a bio-hybrid microswimmer system driven by multiple Serratia marcescens bacteria, we quantify the chemotactic drift of a large number of microswimmers towards L-serine and elucidate the associated collective chemotaxis behavior by statistical analysis of over a thousand swimming trajectories of the microswimmers. The results show that the microswimmers have a strong heading preference for moving up the L-serine gradient, while their speed does not change considerably when moving up and down the gradient; therefore, the heading bias constitutes the major factor that produces the chemotactic drift. The heading direction of a microswimmer is found to be significantly more persistent when it moves up the L-serine gradient than when it travels down the gradient; this effect causes the apparent heading preference of the microswimmers and is the crucial reason that enables the seemingly cooperative chemotaxis of multiple bacteria on a microswimmer. In addition, we find that their chemotactic drift velocity increases superquadratically with their mean swimming speed, suggesting that chemotaxis of bio-hybrid microsystems can be enhanced by designing and building faster microswimmers. Such bio-hybrid microswimmers with chemotactic steering capability may find future applications in targeted drug delivery, bioengineering, and lab-on-a-chip devices.

DOI Project Page [BibTex]

pi Zhuang, J., Sitti, M. Chemotaxis of bio-hybrid multiple bacteria-driven microswimmers Scientific reports, 6, pages: 32135, Nature Publishing Group, March 2016 (article)

DOI Project Page [BibTex]

Targeted drug delivery and imaging using mobile milli/microrobots: A promising future towards theranostic pharmaceutical design

Vikram Singh, A., Sitti, M.

Current Pharmaceutical Design, 22(11):1418-1428, Bentham Science Publishers, March 2016 (article)

Abstract

Miniature untethered medical robots have been receiving growing attention due to technological advances in microactuation, microsensors, and microfabrication and have significant potential to reduce the invasiveness and improve the accessibility of medical devices into unprecedented small spaces inside the human body. In this review, we discuss therapeutic and diagnostic applications of untethered medical microrobots. Wirelessly controlled milli/microrobots with integrated sensors are revolutionizing micromanipulation based medical interventions and are enabling doctors to perform minimally invasive procedures not possible before. 3D fabrication technologies enabling milli/microrobot fabrication at the single cell scale are empowering high-resolution visual imaging and in vivo manipulation capabilities. Swallowable millirobots and injectabale ocular microrobots allow the gastric ulcer imaging, and performance of vitreoretinal microsurgery at previously inaccessible ocular sites. Many invasive excision and incision based diagnostic biopsy, prostrate, and nephrolgical procedures can be performed minimally or almost noninvasively due to recent advancements in microrobotic technology. Advances in biohybrid microrobot systems are pushing microrobotic systems even smaller, using biological cells as on-board microactuators and microsensors using the chemical energy. Such microrobotic systems could be used for local targeted delivery of imaging contrast agents, drugs, genes, and mRNA, minimally invasive surgery, and cell micromanipulation in the near future.

link (url) [BibTex]

pi Vikram Singh, A., Sitti, M. Targeted drug delivery and imaging using mobile milli/microrobots: A promising future towards theranostic pharmaceutical design Current Pharmaceutical Design, 22(11):1418-1428, Bentham Science Publishers, March 2016 (article)

link (url) [BibTex]

Parallel microcracks-based ultrasensitive and highly stretchable strain sensors

Amjadi, M., Turan, M., Clementson, C. P., Sitti, M.

ACS Applied Materials \& Interfaces, 8(8):5618-5626, American Chemical Society, Febuary 2016 (article)

Abstract

There is an increasing demand for flexible, skin-attachable, and wearable strain sensors due to their various potential applications. However, achieving strain sensors with both high sensitivity and high stretchability is still a grand challenge. Here, we propose highly sensitive and stretchable strain sensors based on the reversible microcrack formation in composite thin films. Controllable parallel microcracks are generated in graphite thin films coated on elastomer films. Sensors made of graphite thin films with short microcracks possess high gauge factors (maximum value of 522.6) and stretchability (ε ≥ 50%), whereas sensors with long microcracks show ultrahigh sensitivity (maximum value of 11 344) with limited stretchability (ε ≤ 50%). We demonstrate the high performance strain sensing of our sensors in both small and large strain sensing applications such as human physiological activity recognition, human body large motion capturing, vibration detection, pressure sensing, and soft robotics.

DOI [BibTex]

pi Amjadi, M., Turan, M., Clementson, C. P., Sitti, M. Parallel microcracks-based ultrasensitive and highly stretchable strain sensors ACS Applied Materials \& Interfaces, 8(8):5618-5626, American Chemical Society, Febuary 2016 (article)

DOI [BibTex]

Stretchable, Skin-Mountable, and Wearable Strain Sensors and Their Potential Applications: A Review

Amjadi, M., Kyung, K., Park, I., Sitti, M.

Advanced Functional Materials, 26, pages: 1678-1698, Febuary 2016 (article)

Abstract

There is a growing demand for flexible and soft electronic devices. In particular, stretchable, skin-mountable, and wearable strain sensors are needed for several potential applications including personalized health-monitoring, human motion detection, human-machine interfaces, soft robotics, and so forth. This Feature Article presents recent advancements in the development of flexible and stretchable strain sensors. The article shows that highly stretchable strain sensors are successfully being developed by new mechanisms such as disconnection between overlapped nanomaterials, crack propagation in thin films, and tunneling effect, different from traditional strain sensing mechanisms. Strain sensing performances of recently reported strain sensors are comprehensively studied and discussed, showing that appropriate choice of composite structures as well as suitable interaction between functional nanomaterials and polymers are essential for the high performance strain sensing. Next, simulation results of piezoresistivity of stretchable strain sensors by computational models are reported. Finally, potential applications of flexible strain sensors are described. This survey reveals that flexible, skin-mountable, and wearable strain sensors have potential in diverse applications while several grand challenges have to be still overcome.

DOI [BibTex]

pi Amjadi, M., Kyung, K., Park, I., Sitti, M. Stretchable, Skin-Mountable, and Wearable Strain Sensors and Their Potential Applications: A Review Advanced Functional Materials, 26, pages: 1678-1698, Febuary 2016 (article)

DOI [BibTex]

Size optimization of a magnetic system for drug delivery with capsule robots

Munoz, F., Alici, G., Li, W., Sitti, M.

IEEE Transactions on Magnetics, 52(5):1-11, IEEE, January 2016 (article)

Abstract

In this paper, we present a methodology for the size optimization of an external magnetic system made of arc-shaped permanent magnets (ASMs). This magnetic system is able to remotely actuate a drug-release module embedded in a prototype of a capsule robot. The optimization of the magnetic system is carried out by using an accurate analytical model that is valid for any arbitrary dimensions of the ASMs. By using this analytical model, we perform parametric studies and conduct a statistical analysis [analysis of variance (ANOVA)] to investigate efficient ways to distribute the volume of the ASMs so that the dimensions and volume of the magnetic system are minimized while optimal flux densities and magnetic torques are obtained to actuate the drug delivery system (DDS). The ANOVA results, at 5% significance level, indicate that changes in the angular width followed by changes in the length of the ASMs have the highest impact on the magnetic linkage. Furthermore, our experimental results, which are in agreement with the analytical results, show that the size optimization of the magnetic system is effective for the actuation of the DDS in capsule robots.

DOI [BibTex]

pi Munoz, F., Alici, G., Li, W., Sitti, M. Size optimization of a magnetic system for drug delivery with capsule robots IEEE Transactions on Magnetics, 52(5):1-11, IEEE, January 2016 (article)

DOI [BibTex]

Momentum Control with Hierarchical Inverse Dynamics on a Torque-Controlled Humanoid

Herzog, A., Rotella, N., Mason, S., Grimminger, F., Schaal, S., Righetti, L.

Autonomous Robots, 40(3):473-491, 2016 (article)

Abstract

Hierarchical inverse dynamics based on cascades of quadratic programs have been proposed for the control of legged robots. They have important benefits but to the best of our knowledge have never been implemented on a torque controlled humanoid where model inaccuracies, sensor noise and real-time computation requirements can be problematic. Using a reformulation of existing algorithms, we propose a simplification of the problem that allows to achieve real-time control. Momentum-based control is integrated in the task hierarchy and a LQR design approach is used to compute the desired associated closed-loop behavior and improve performance. Extensive experiments on various balancing and tracking tasks show very robust performance in the face of unknown disturbances, even when the humanoid is standing on one foot. Our results demonstrate that hierarchical inverse dynamics together with momentum control can be efficiently used for feedback control under real robot conditions.

am mg

link (url) DOI [BibTex]

am mg Herzog, A., Rotella, N., Mason, S., Grimminger, F., Schaal, S., Righetti, L. Momentum Control with Hierarchical Inverse Dynamics on a Torque-Controlled Humanoid Autonomous Robots, 40(3):473-491, 2016 (article)

link (url) DOI [BibTex]

2011

Design and application of a wire-driven bidirectional telescopic mechanism for workspace expansion with a focus on shipbuilding tasks

Lee, D., Chang, D., Shin, Y., Son, D., Kim, T., Lee, K., Kim, J.

Advanced Robotics, 25, 2011 (article)

[BibTex]

2011

pi Lee, D., Chang, D., Shin, Y., Son, D., Kim, T., Lee, K., Kim, J. Design and application of a wire-driven bidirectional telescopic mechanism for workspace expansion with a focus on shipbuilding tasks Advanced Robotics, 25, 2011 (article)

[BibTex]

Waalbot II: Adhesion recovery and improved performance of a climbing robot using fibrillar adhesives

Murphy, M. P., Kute, C., Mengüç, Y., Sitti, M.

The International Journal of Robotics Research, 30(1):118-133, SAGE Publications Sage UK: London, England, 2011 (article)

Project Page [BibTex]

pi Murphy, M. P., Kute, C., Mengüç, Y., Sitti, M. Waalbot II: Adhesion recovery and improved performance of a climbing robot using fibrillar adhesives The International Journal of Robotics Research, 30(1):118-133, SAGE Publications Sage UK: London, England, 2011 (article)

Project Page [BibTex]

Automated Control of AFM Based Nanomanipulation

Xie, H., Onal, C., Régnier, S., Sitti, M.

In Atomic Force Microscopy Based Nanorobotics, pages: 237-311, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

pi Xie, H., Onal, C., Régnier, S., Sitti, M. Automated Control of AFM Based Nanomanipulation In Atomic Force Microscopy Based Nanorobotics, pages: 237-311, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

Automated 2-D nanoparticle manipulation using atomic force microscopy

Onal, C. D., Ozcan, O., Sitti, M.

IEEE Transactions on Nanotechnology, 10(3):472-481, IEEE, 2011 (article)

[BibTex]

pi Onal, C. D., Ozcan, O., Sitti, M. Automated 2-D nanoparticle manipulation using atomic force microscopy IEEE Transactions on Nanotechnology, 10(3):472-481, IEEE, 2011 (article)

[BibTex]

Biaxial mechanical modeling of the small intestine

Bellini, C., Glass, P., Sitti, M., Di Martino, E. S.

Journal of the mechanical behavior of biomedical materials, 4(8):1727-1740, Elsevier, 2011 (article)

Project Page [BibTex]

pi Bellini, C., Glass, P., Sitti, M., Di Martino, E. S. Biaxial mechanical modeling of the small intestine Journal of the mechanical behavior of biomedical materials, 4(8):1727-1740, Elsevier, 2011 (article)

Project Page [BibTex]

Teleoperation Based AFM Manipulation Control

Xie, H., Onal, C., Régnier, S., Sitti, M.

In Atomic Force Microscopy Based Nanorobotics, pages: 145-235, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

pi Xie, H., Onal, C., Régnier, S., Sitti, M. Teleoperation Based AFM Manipulation Control In Atomic Force Microscopy Based Nanorobotics, pages: 145-235, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

Descriptions and challenges of AFM based nanorobotic systems

Xie, H., Onal, C., Régnier, S., Sitti, M.

In Atomic Force Microscopy Based Nanorobotics, pages: 13-29, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

pi Xie, H., Onal, C., Régnier, S., Sitti, M. Descriptions and challenges of AFM based nanorobotic systems In Atomic Force Microscopy Based Nanorobotics, pages: 13-29, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

Assembly and disassembly of magnetic mobile micro-robots towards deterministic 2-D reconfigurable micro-systems

Diller, E., Pawashe, C., Floyd, S., Sitti, M.

The International Journal of Robotics Research, 30(14):1667-1680, SAGE Publications Sage UK: London, England, 2011 (article)

[BibTex]

pi Diller, E., Pawashe, C., Floyd, S., Sitti, M. Assembly and disassembly of magnetic mobile micro-robots towards deterministic 2-D reconfigurable micro-systems The International Journal of Robotics Research, 30(14):1667-1680, SAGE Publications Sage UK: London, England, 2011 (article)

[BibTex]

Toward simple control for complex, autonomous robotic applications: combining discrete and rhythmic motor primitives

Degallier, S., Righetti, L., Gay, S., Ijspeert, A.

Autonomous Robots, 31(2-3):155-181, October 2011 (article)

Abstract

Vertebrates are able to quickly adapt to new environments in a very robust, seemingly effortless way. To explain both this adaptivity and robustness, a very promising perspective in neurosciences is the modular approach to movement generation: Movements results from combinations of a finite set of stable motor primitives organized at the spinal level. In this article we apply this concept of modular generation of movements to the control of robots with a high number of degrees of freedom, an issue that is challenging notably because planning complex, multidimensional trajectories in time-varying environments is a laborious and costly process. We thus propose to decrease the complexity of the planning phase through the use of a combination of discrete and rhythmic motor primitives, leading to the decoupling of the planning phase (i.e. the choice of behavior) and the actual trajectory generation. Such implementation eases the control of, and the switch between, different behaviors by reducing the dimensionality of the high-level commands. Moreover, since the motor primitives are generated by dynamical systems, the trajectories can be smoothly modulated, either by high-level commands to change the current behavior or by sensory feedback information to adapt to environmental constraints. In order to show the generality of our approach, we apply the framework to interactive drumming and infant crawling in a humanoid robot. These experiments illustrate the simplicity of the control architecture in terms of planning, the integration of different types of feedback (vision and contact) and the capacity of autonomously switching between different behaviors (crawling and simple reaching).

link (url) DOI [BibTex]

mg Degallier, S., Righetti, L., Gay, S., Ijspeert, A. Toward simple control for complex, autonomous robotic applications: combining discrete and rhythmic motor primitives Autonomous Robots, 31(2-3):155-181, October 2011 (article)

link (url) DOI [BibTex]

Applications of AFM Based Nanorobotic Systems

Xie, H., Onal, C., Régnier, S., Sitti, M.

In Atomic Force Microscopy Based Nanorobotics, pages: 313-342, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

pi Xie, H., Onal, C., Régnier, S., Sitti, M. Applications of AFM Based Nanorobotic Systems In Atomic Force Microscopy Based Nanorobotics, pages: 313-342, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

Modeling of stochastic motion of bacteria propelled spherical microbeads

Arabagi, V., Behkam, B., Cheung, E., Sitti, M.

Journal of Applied Physics, 109(11):114702, AIP, 2011 (article)

Project Page [BibTex]

pi Arabagi, V., Behkam, B., Cheung, E., Sitti, M. Modeling of stochastic motion of bacteria propelled spherical microbeads Journal of Applied Physics, 109(11):114702, AIP, 2011 (article)

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The effect of aspect ratio on adhesion and stiffness for soft elastic fibres

Aksak, B., Hui, C., Sitti, M.

Journal of The Royal Society Interface, 8(61):1166-1175, The Royal Society, 2011 (article)

Project Page [BibTex]

pi Aksak, B., Hui, C., Sitti, M. The effect of aspect ratio on adhesion and stiffness for soft elastic fibres Journal of The Royal Society Interface, 8(61):1166-1175, The Royal Society, 2011 (article)

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Nanomechanics of AFM based nanomanipulation

Xie, H., Onal, C., Régnier, S., Sitti, M.

In Atomic Force Microscopy Based Nanorobotics, pages: 87-143, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

pi Xie, H., Onal, C., Régnier, S., Sitti, M. Nanomechanics of AFM based nanomanipulation In Atomic Force Microscopy Based Nanorobotics, pages: 87-143, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

Enhancing adhesion of biologically inspired polymer microfibers with a viscous oil coating

Cheung, E., Sitti, M.

The Journal of Adhesion, 87(6):547-557, Taylor & Francis Group, 2011 (article)

Project Page [BibTex]

pi Cheung, E., Sitti, M. Enhancing adhesion of biologically inspired polymer microfibers with a viscous oil coating The Journal of Adhesion, 87(6):547-557, Taylor & Francis Group, 2011 (article)

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Instrumentation Issues of an AFM Based Nanorobotic System

Xie, H., Onal, C., Régnier, S., Sitti, M.

In Atomic Force Microscopy Based Nanorobotics, pages: 31-86, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

pi Xie, H., Onal, C., Régnier, S., Sitti, M. Instrumentation Issues of an AFM Based Nanorobotic System In Atomic Force Microscopy Based Nanorobotics, pages: 31-86, Springer Berlin Heidelberg, 2011 (incollection)

[BibTex]

Piezoelectric polymer fiber arrays for tactile sensing applications

Sümer, B., Aksak, B., Şsahin, K., Chuengsatiansup, K., Sitti, M.

Sensor Letters, 9(2):457-463, American Scientific Publishers, 2011 (article)

Project Page [BibTex]

pi Sümer, B., Aksak, B., Şsahin, K., Chuengsatiansup, K., Sitti, M. Piezoelectric polymer fiber arrays for tactile sensing applications Sensor Letters, 9(2):457-463, American Scientific Publishers, 2011 (article)

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Control methodologies for a heterogeneous group of untethered magnetic micro-robots

Floyd, S., Diller, E., Pawashe, C., Sitti, M.

The International Journal of Robotics Research, 30(13):1553-1565, SAGE Publications, 2011 (article)

[BibTex]

pi Floyd, S., Diller, E., Pawashe, C., Sitti, M. Control methodologies for a heterogeneous group of untethered magnetic micro-robots The International Journal of Robotics Research, 30(13):1553-1565, SAGE Publications, 2011 (article)

[BibTex]