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Department Talks

Liquid-elastomer composites: from basic physics to functional materials

Talk
  • 04 November 2019 • 11:00 12:00
  • Eric R. Dufresne
  • MPI-IS Stuttgart, Room 2P4, Heisenbergstraße 3

Prof. Eric Dufresne will describe some experiments on some simple composites of elastomers and droplets. First, we will consider their composite mechanical properties. He will show how simple liquid droplets can counterintuitively stiffen the material, and how magnetorheological fluid droplets can provide elastomers with magnetically switchable shape memory. Second, we consider the nucleation, growth, and ripening of droplets within an elastomer. Here, a variety of interesting phenomena emerge: size-tunable monodisperse droplets, shape-tunable droplets, and ripening of droplets along stiffness gradients. We are exploiting these phenomena to make materials with mechanically switchable structural color.

Organizers: Metin Sitti


Electromechanical transducers for energy harvesting, sensing, and actuation

Talk
  • 08 November 2019 • 11:00 12:00
  • Majid Taghavi
  • MPI-IS Stuttgart, Room 2P4, Heisenbergstraße 3

In this talk, Majid TaghaviI will briefly discuss the demand for high-performance electromechanical transducers, the current challenges, and approaches he has been pursuing to tackle them. He will discuss multiple electromechanical concepts and devices that he has delivered for low-power energy harvesting, self-powered sensors, and artificial muscle technologies. Majid Taghavi will look into piezoelectric, triboelectric, electrostatic, dielectrophoretic, and androphilic phenomena, and will show my observations and innovations in coupling physical phenomena and developing smart materials and intelligent devices.

Organizers: Metin Sitti

  • Prof. Pietro Valdastri and Prof. Russel Harris
  • Room 2P4, Heisenbergstraße 3, 70569 Stuttgart

Prof. Pietro Valdastri's talk will focus on Medical Capsule Robots. Capsule robots are cm-size devices that leverage extreme miniaturization to access and operate in environments that are out of reach for larger robots. In medicine, capsule robots can be designed to be swallowed like a pill and to diagnose and treat mortal diseases, such as cancer. The talk will move from capsule robots for the inspection of the digestive tract toward a new generation of surgical robots and devices, having a relevant reduction in size, invasiveness, and cost as the main drivers for innovation. During the talk, we will discuss the recent enabling technologies that are being developed at the University of Leeds to transform medical robotics. These technologies include magnetic manipulation of capsule robots, hydraulic and pneumatic actuation, real-time tracking of capsule position and orientation, ultra-low-cost design, frugal innovation, and autonomy in robotic endoscopy.
Prof. Russell Harris has been researching new manufacturing processes for over 20 years. He has several research projects focussing on robotics, and is particularly interested in how new manufacturing processes can be an enabler to advanced robotic devices and components. In this talk he will discuss some of this research and where he believes there may be new opportunities for collaborative research across manufacturing and robotics.


Soft Aerial Robotics for Infrastructure Manufacturing

Talk
  • 26 September 2019 • 14:00 15:00
  • Mirko Kovac
  • 2R04

Future cities and infrastructure systems will evolve into complex conglomerates where autonomous aerial, aquatic and ground-based robots will coexist with people and cooperate in symbiosis. To create this human-robot ecosystem, robots will need to respond more flexibly, robustly and efficiently than they do today. They will need to be designed with the ability to move across terrain boundaries and physically interact with infrastructure elements to perform sensing and intervention tasks. Taking inspiration from nature, aerial robotic systems can integrate multi-functional morphology, new materials, energy-efficient locomotion principles and advanced perception abilities that will allow them to successfully operate and cooperate in complex and dynamic environments. This talk will describe the scientific fundamentals, design principles and technologies for the development of biologically inspired flying robots with adaptive morphology that can perform monitoring and manufacturing tasks for future infrastructure and building systems. Examples will include flying robots with perching capabilities and origami-based landing systems, drones for aerial construction and repair, and combustion-based jet thrusters for aerial-aquatic vehicles.

Organizers: Metin Sitti


  • Peter Blümler
  • MPI-IS Stuttgart, Heisenbergstr. 3, room 2P04

A new concept of using permanent magnet systems for guiding superparamagnetic nano-particles (SPP) on arbitrary trajectories over a large volume is presented. The same instrument can also be used for magnetic resonance imaging (MRI) using the inherent contrast of the SPP [1]. The basic idea is to use one magnet system, which provides a strong, homogeneous, dipolar magnetic field to magnetize and orient the particles, and a second constantly graded, quadrupolar field, superimposed on the first, to generate a force on the oriented particles. As a result, particles are guided with constant force and in a single direction over the entire volume. Prototypes of various sizes were constructed to demonstrate the principle in two dimensions on several nanoparticles, which were moved along a rough square by manual adjustment of the force angle [1]. Surprisingly even SPP with sizes < 100 nm could be moved with speeds exceeding 10 mm/s due to reversible agglomeration, for which a first hydrodynamic model is presented. Furthermore, a more advanced system with two quadrupoles is presented which allows canceling the force, hence stopping the SPP and moving them around sharp edges. Additionally, this system also allows for MRI and some first experiments are presented. Recently this concept was combined with liquid crystalline elastomers with incorporated SPP to create “micro-robots” whose coarse maneuvers are performed by a MagGuider-system while there microscopic actuation is controlled either by light or temperature [2]. 1. O. Baun, PB, JMMM 439 (2017) 294-304. doi: 10.1016/j.jmmm.2017.05.001 2. D. Ditter, PB et al. Adv. Functional Mater. 1902454 (2019) doi: 10.1002/adfm.201902454

Organizers: Metin Sitti


An introduction to bladder cancer & challenges for translational research

Talk
  • 22 July 2019 • 10:30 AM - 22 April 2019 • 11:30 AM
  • Richard T Bryan
  • 2P4


  • Joseph B. Tracy
  • MPI-IS Stuttgart, Room 2P04

Magnetic fields and light can be used to assemble, manipulate, and heat nanoparticles (NPs) and to remotely actuate polymer composites. Simple soft robots will be presented, where incorporation of magnetic and plasmonic NPs makes them responsive to magnetic fields and light. Application of magnetic fields to dispersions of magnetic NPs drives their assembly into chains. Dipolar coupling within the chains is a source of magnetic anisotropy, and chains of magnetic NPs embedded in a polymer matrix can be used to program the response of soft robots, while still using simple architectures. Wavelength-selective photothermal triggering of shape recovery in shape memory polymers with embedded Au nanospheres and nanorods can be used to remotely drive sequential processes. Combining magnetic actuation and photothermal heating enables remote configuration, locking, unlocking, and reconfiguration of soft robots, thus increasing their capabilities. Composite and multifunctional NPs are of interest for expanding the properties and applications of NPs. Silica shells are desirable for facilitating functionalization with silanes and enhancing the stability of NPs. Methods for depositing thin silica shells with controlled morphologies onto Au nanorods and CdSe/CdS core/shell quantum dot nanorods will be presented. Silica deposition can also be accompanied by etching and breakage of the core NPs. Assembly of Fe3O4 NPs onto silica-overcoated Au nanorods allows for magnetic manipulation, while retaining the surface plasmon resonance.

Organizers: Metin Sitti


  • Prof. Shu Yang
  • 2P04

Geometry is concerned with the properties of configurations of points, lines, and circles, while topology is concerned with space, dimension, and transformation. Geometry is also materials independent and scale invariant. By introducing holes and cuts in 2D sheets, we demonstrate dramatic shape change and super-conformability via expanding or collapsing of the hole arrays without deforming individual lattice units. When choosing the cuts and geometry correctly, we show folding into the third dimension, known as kirigami. The kirigami structures can be rendered pluripotent, that is changing into different 3D structures from the same 2D sheet. We explore their potential applications in energy efficient building facade, super-stretchable and shape conformable energy storage devices and medical devices, as well as bioinspired robotics. Programmable shape-shifting materials can take different physical forms to achieve multifunctionality in a dynamic and controllable manner. Through designs of geometric surface patterns, e.g. microchannels, we program the orientational elasticity in liquid crystal elastomers (LCEs), to direct folding of the 2D sheets into 3D shapes, which can be triggered by heat, light, and electric field. Taking this knowledge of guided inhomogeneous local deformations in LCEs, we then tackle the inverse problem – pre-programming geometry on a flat sheet to take an arbitrary desired 3D shape. Lastly, I will show the prospective of taking geometry to create smart fabrics and tendon-like filaments for soft robotic applications.


  • Jérôme Casas
  • 2P04

Insect chemical ecology is a mature, long standing field, with its own journal. By contrast, insect physical ecology is much less studied and the worked scattered. Using work done in my group, I will highlight locomotion, both in granular materials like sand and at the water surface as well as sensing, in particular olfaction and flow sensing. The bio-inspired implementations in MEMS technologies will be the closing chapter.

Organizers: Metin Sitti


  • Sangram Bagh
  • 2P04

The molecular connectivity between genes and proteins inside a cell shows a good degree of resemblance with complex electrical circuits. This inspires the possibility of engineering a cell similar to an engineering device by plugging in genetic logic circuits. This approach, which is loosely defined as synthetic biology is an emerging field of bioengineering, where scientist use electrical and computer engineering principle to re-program cellular functions with a potential to solve next generation challenges in medicine, materials, energy, and space travel. In this talk, we discuss our efforts to create artificial and complex chemical signal processing systems using genetic logic circuits and its applications in building a technology platform for microbial robotics. We further discuss our systems biology effort to understand the effect of microgravity on human and bacterial cells during space travel.

Organizers: Metin Sitti


  • Ingmar H. Riedel-Kruse
  • Max-Planck-Institute for Intelligent Systems, Heisenbergstraße 3, Stuttgart, Room 2P4

I will share my vision that microbiological systems should be as programmable, interactive, accessible, constructible, and useful as our personal electronic devices. Natural multi-cellular organisms and symbiotic systems achieve complex tasks through division of labor among cells. Such systems transcend current electronics and robotics in many ways, e.g., they synthesize chemicals, generate active physical forms, and self-replicate. Harnessing these features promises significant impact for manufacturing (bioelectronics / smart materials /swarm robotics), health (tissue engineering), chemistry (pathway modularization), ecology (bioremediation), biodesign (art), and more. My lab takes a synergistic bottom-up / top-down approach to achieve such transformative applications: (1) We utilize synthetic biology and biophysics approaches to engineer and understand multi-cell bacterial assemblies. We developed the first synthetic cell-cell adhesion toolbox [1] and optogenetic cell-surface adhesion toolbox (‘Biofilm Lithography’) [2]. Integration with standard synthetic biology components (e.g., for signaling, differentiation, logic) now enables a new intelligent materials paradigm that rests on versatile, modular, and composable smart particles (i.e., cells). (2) We pioneered ‘Interactive Biotechnology’ that enables humans to directly interact with living multi-cell assemblies in real-time. I will provide the rational for this interactivity, demonstrate multiple applications using phototactic Euglena cells (e.g., tangible museum exhibits [3], biology cloud experimentation labs [4], biotic video games [5]), and show how this technology aided the discovery of new microswimmer phototaxis control strategies [6]. Finally, I discuss architecture and swarm programming languages for future bio-electronic devices (i.e., ‘Biotic Processing Units’ – BPUs) [7,8]. REFs: [1] Glass, Cell ’18; [2] Jin, PNAS ’18; [3] Lee, CHI ACM ’15; [4] Hossain, Nature Biotech ‘16; [5] Cira, PLoS Biology ‘15; [6] Tsang, Nature Physics ’18; [7] Lam LOC ‘17; [8] Washington, PNAS ‘19.


  • Dr. František Mach
  • Stuttgart 2P4

The state-of-the-art robotic systems adopting magnetically actuated ferromagnetic bodies or even whole miniature robots have recently become a fast advancing technological field, especially at the nano and microscale. The mesoscale and above all multiscale magnetically guided robotic systems appear to be the advanced field of study, where it is difficult to reflect different forces, precision and also energy demands. The major goal of our talk is to discuss the challenges in the field of magnetically guided mesoscale and multiscale actuation, followed by the results of our research in the field of magnetic positioning systems and the magnetic soft-robotic grippers.

Organizers: Metin Sitti