Publications (21)
Observation of the Faraday effect via beam deflection in a longitudinal magnetic field
Ambarish Ghosh, Peer Fischer
We report the observation of the magnetic field induced circular differential deflection of light at the interface of a Faraday medium. The difference in the angles of refraction o…
Multi-channel free-space optical convolutions with incoherent light
Alexander Song, Sai Nikhilesh Murty Kottapalli, Peer Fischer
Free-space optical systems are promising candidates for high performance computing and have been particularly successful in the implementation of large-scale convolutions. Convolut…
A right-handed isotropic medium with a negative refractive index
Yi-Fan Chen, Peer Fischer, Frank W. Wise
The sign of the refractive index of any medium is soley determined by the requirement that the propagation of an electromagnetic wave obeys Einstein causality. Our analysis shows t…
Absolute diffusion measurements of active enzyme solutions by NMR
Jan-Philipp Günther, Günter Majer, Peer Fischer
The diffusion of enzymes is of fundamental importance for many biochemical processes. Enhanced or directed enzyme diffusion can alter the accessibility of substrates and the organi…
Characterization of active matter in dense suspensions with heterodyne laser Doppler velocimetry
Johannes Sachs, S. Nikhilesh Kottapalli, Peer Fischer +2
We present a novel approach for characterizing the properties and performance of active matter in dilute suspension as well as in crowded environments. We use Super-Heterodyne Lase…
Gait learning for soft microrobots controlled by light fields
Alexander von Rohr, Sebastian Trimpe, Alonso Marco +2
Soft microrobots based on photoresponsive materials and controlled by light fields can generate a variety of different gaits. This inherent flexibility can be exploited to maximize…
Spatiotemporal Thermal Modulation and Patterning using a Programmable 1024 Element Microheater Array
Rahul Goyal, Jang-Hwan Han, Sadaf Pashapour +1
Programmable microheater arrays are essential for a variety of applications including gas sensing, microfluidic lab on a chip devices, 3D printers, and biosensors that rely on DNA…
Low-power scalable multilayer optoelectronic neural networks enabled with incoherent light
Alexander Song, Sai Nikhilesh Murty Kottapalli, Rahul Goyal +2
Optical approaches have made great strides towards the goal of high-speed, energy-efficient computing necessary for modern deep learning and AI applications. Read-in and read-out o…
Highly stable, reactive and ultrapure nanoporous metallic films
Hyunah Kwon, Hannah-Noa Barad, Alex Ricardo Silva Olaya +5
Nanoporous metals possess unique properties attributed to their high surface area and interconnected nanoscale ligaments. They are mostly fabricated by wet synthetic methods involv…
Ultrasonic metamaterial at MHz frequencies using microstructured glass
Oscar Demeulenaere, Nikita Ustimenko, Athanasios G. Athanassiadis +3
Acoustic metamaterials enhance traditional material properties through microstructure engineering, providing new opportunities to shape sound fields in applications ranging from bi…
Engineering wavefronts with machine learned structured polarization
Sai Nikhilesh Murty Kottapalli, Alexander Song, Peer Fischer
Optical approaches for wavefront shaping traditionally rely on phase modulation through holographic techniques. Shaping the phase determines a wave's diffraction and hence its inte…
Active colloidal propulsion over a crystalline surface
Udit Choudhury, Arthur V. Straube, Peer Fischer +2
We study both experimentally and theoretically the dynamics of chemically self-propelled Janus colloids moving atop a two-dimensional crystalline surface. The surface is a hexagona…
Spatially Selective Acoustic Pressure Reporting Using Antibubbles
Nicolas Moreno Gomez, Athanasios G. Athanassiadis, Fabian Reuter +5
Ultrasound offers promising applications in biology and chemistry, but quantifying local ultrasound conditions remains challenging due to the lack of non-invasive measurement tools…
Dry synthesis of bi-layer nanoporous metal films as plasmonic metamaterial
Vincenzo Caligiuri, Hyunah Kwon, Andrea Griesi +13
Nanoporous metals are a class of nanostructured materials finding extensive applications in multiple fields thanks to their unique properties attributed to their high surface area…
Janus particles with coupled electric and magnetic moments make a disordered magneto-electric medium
Ambarish Ghosh, Nicholas K. Sheridon, Peer Fischer
We demonstrate that by combining permanent electric and magnetic moments in particles, it is possible to realize a new type of medium that allows for a cross-correlation between el…
The role of symmetry in driven propulsion at low Reynolds number
Johannes Sachs, Konstantin I. Morozov, Oded Kenneth +4
We theoretically and experimentally investigate low-Reynolds-number propulsion of geometrically achiral planar objects that possess a dipole moment and that are driven by a rotatin…
Chiral molecules split light: Reflection and refraction in a chiral liquid
Ambarish Ghosh, Peer Fischer
A light beam changes direction as it enters a liquid at an angle from another medium, such as air. Should the liquid contain molecules that lack mirror symmetry, then it has been p…
Chiral Plasmonic Hydrogen Sensors
Marcus Matuschek, Dhruv Pratap Singh, Hyeon-Ho Jeong +5
In this article, a chiral plasmonic hydrogen-sensing platform using palladium-based nanohelices is demonstrated. Such 3D chiral nanostructures fabricated by nanoglancing angle depo…
Antibubbles enable tunable payload release with low-intensity ultrasound
Nicolas Moreno-Gomez, Athanasios G. Athanassiadis, Albert T. Poortinga +1
The benefits of ultrasound are its ease-of-use and its ability to precisely deliver energy in opaque and complex media. However, most materials responsive to ultrasound show a weak…
Copper-based disordered plasmonic system with dense nanoisland morphology
Tlek Tapani, Roman Krahne, Vincenzo Caligiuri +14
Dry synthesis is a highly versatile method for the fabrication of nanoporous metal films, since it enables easy and reproducible deposition of single or multi-layer(s) of nanostruc…
Directed Acoustic Assembly in 3D
Kai Melde, Minghui Shi, Heiner Kremer +7
The creation of whole 3D objects in one shot is an ultimate goal for rapid prototyping, most notably biofabrication, where conventional methods are typically slow and apply mechani…