Abstract Self-propelled bacteria can be integrated into synthetic micromachines and act as biological propellers. So far, proposed designs suffer from low reproducibility, large noise levels or lack of tunability. Here we demonstrate that fast, reliable tunable bio-hybrid micromotors obtained by the self-assembly structures with genetically engineered The components consist 3D interconnected having a rotating unit capture individual an array microchambers so cells contribute maximally to...

Many motile microorganisms react to environmental light cues with a variety of motility responses guiding cells towards better conditions for survival and growth. The use spatial modulators could help elucidate the mechanisms photo-movements while, at same time, providing an efficient strategy achieve temporal control cell concentration. Here we demonstrate that millions bacteria, genetically modified swim smoothly controllable speed, can be arranged into complex reconfigurable density...

This work primarily aims to fabricate and use two photon polymerization (2PP) microstructures capable of being optically manipulated into any arbitrary orientation. We have integrated optical waveguides the structures therefore freestanding waveguides, which can be positioned anywhere in sample at orientation using traps. One key aspects is change direction incident plane wave, marked increase numerical aperture demonstrated. Hence, steered waveguide tap from a relatively broader beam then...

Hydrodynamic synchronization is a fundamental physical phenomenon by which self-sustained oscillators communicate through perturbations in the surrounding fluid and converge to stable synchronized state. This an important factor for emergence of regular coordinated patterns motions cilia flagella. When dealing with biological systems, however, it always hard disentangle internal signaling mechanisms from external purely couplings. We have used combination two-photon polymerization...

Two-photon polymerization enables the fabrication of micron sized structures with submicron resolution.Spatial light modulators (SLM) have already been used to create multiple polymerizing foci in photoresist by holographic beam shaping, thus enabling parallel microstructures.Here we demonstrate two-photon single 3D microstructures holographically translated foci.Multiple were created phase holograms, which calculated real-time on an NVIDIA CUDA GPU, and displayed electronically addressed...

Precisely controlled manipulation of nonadherent single cells is often a pre-requisite for their detailed investigation. Optical trapping provides versatile means positioning with submicrometer precision or measuring forces femto-Newton resolution. A variant the technique, called indirect optical trapping, enables single-cell no photodamage and superior spatial control stability by relying on optically trapped microtools biochemically bound to cell. High-resolution 3D lithography prepare...

Abstract Biohybrid microbots integrate biological actuators and sensors into synthetic chassis with the aim of providing building blocks next‐generation micro‐robotics. One main challenges is development self‐assembled systems consistent behavior such that they can be controlled independently to perform complex tasks. Herein, it shown that, using light‐driven bacteria as propellers, 3D printed steered by unbalancing light intensity over different microbot parts. An optimal feedback loop...

Blood–brain barrier (BBB) models derived from human stem cells are powerful tools to improve our understanding of cerebrovascular diseases and facilitate drug development for the brain. Yet providing cell–derived endothelial with right signaling cues acquire BBB characteristics while also retaining their vascular identity remains challenging. Here, we show that simultaneous activation cyclic AMP Wnt/β-catenin inhibition TGF-β pathway in robustly induce properties vitro. To target this...

Abstract Quorum sensing (QS) is a communication form between bacteria via small signal molecules that enables global gene regulation as function of cell density. We applied microfluidic mother machine to study the kinetics QS response Pseudomonas aeruginosa additions and withdrawals molecules. traced fast buildup subsequent considerably slower decay population-level single-cell-level response. mathematical model explain results quantitatively. found significant heterogeneity in on...

We introduce a system of light driven microscopic autonomous moving particles that move on flat surface. The design is simple, yet effective: Micrometer sized objects with wedge shape are produced by photopolymerization, they covered reflective When the area motion illuminated perpendicularly from above, deflected to side shaped objects, in direction determined position and orientation particles. momentum change during reflection provides driving force for an effectively motion. efficient...

We introduce a method that combines two-photon polymerization (TPP) and surface functionalization to enable the indirect optical manipulation of live cells. TPP-made 3D microstructures were coated specifically with multilayer protein streptavidin non-specifically IgG antibody using polyethylene glycol diamine as linker molecule. Protein density on their surfaces was quantified for various coating methods. The streptavidin-coated structures shown attach biotinated cells reproducibly....

Abstract Living organisms often display adaptive strategies that allow them to move efficiently even in strong confinement. With one single degree of freedom, the angle a rotating bundle flagella, bacteria provide simplest examples locomotion living world. Here we show purely physical mechanism, depending on hydrodynamic stability condition, is responsible for confinement induced transition between two swimming states E. coli . While large channels always crash onto confining walls, when...

Abstract Colloidal particles immersed in a dynamic speckle pattern experience an optical force that fluctuates both space and time. The resulting dynamics presents many interesting analogies with broad class of non-equilibrium systems like: active colloids, self propelled microorganisms, transport dynamical intracellular environments. Here we show the use spatial light modulator allows to generate fields fluctuate controllable time correlations prescribed average intensity profile. In...

Clinical and experimental results with inhaled sodium bicarbonate as an adjuvant therapy in cystic fibrosis (CF) are promising due to its mucolytic bacteriostatic properties, but direct effect has not been studied on respiratory epithelial cells. Our aim was establish characterize co-culture models of human CF bronchial (CFBE) cell lines expressing a wild-type (WT) or mutant (deltaF508) transmembrane conductance regulator (CFTR) channel vascular endothelial cells investigate the effects...

Optical trapping and manipulation typically relies on shaping focused light to control the optical force, usually spherical objects.However, one can also shape object deflection arising from light-matter interaction and, hence, achieve desired optomechanical effects.In this work we look into aspect its potential for controlled manipulation.Using a simple bent waveguide as example, our numerical simulations show that guided of efficiently converts incident momentum force with...

To any energy flow there is an associated of momentum, so that recoil forces arise every time object absorbs or deflects incoming energy. This same principle governs the operation macroscopic turbines as well microscopic use light working fluid. However, a controlled and precise redistribution optical not easy to achieve at micron scale resulting in low efficiency power torque conversion. Here we direct laser writing fabricate 3D guiding structures, shaped garden sprinkler, can precisely...

Abstract Motile cells often explore natural environments characterized by a high degree of structural complexity. Moreover cell motility is also intrinsically noisy due to spontaneous random reorientations and speed fluctuations. This interplay internal external noise sources gives rise complex dynamical behavior that can be strongly sensitive details hard model quantitatively. In striking contrast this general picture we show the mean residence time swimming bacteria inside artificial...

A cell elasticity measurement method is introduced that uses polymer microtools actuated by holographic optical tweezers. The were prepared with two-photon polymerization. Their shape enables the approach of cells in any lateral direction. In presented case, endothelial grown on vertical walls probed tools a use specially shaped prevents target from photodamage may arise during trapping. position was recorded simply video microscopy and analyzed image processing methods. We critically...

3D microstructures partially covered by silver nanoparticles have been developed and tested for surface-enhanced Raman spectroscopy (SERS) in combination with optical tweezers. The made two-photon polymerization of SU-8 photoresist were manipulated a dual beam trap. active area the structures was SERS-active layer using chemically assisted photoreduction from nitrate solutions. Silver layers different grain size distributions created changing parameters characterized scanning electron...

Targeting nanoparticles as drug delivery platforms is crucial to facilitate their cellular entry. Docking of by targeting ligands on cell membranes the first step for initiation uptake. As a model system, we studied brain microvascular endothelial cells, which form anatomical basis blood–brain barrier, and tripeptide glutathione, one most effective cross barrier. To investigate this initial docking between glutathione membrane living applied our recently developed innovative optical method....

Fluorescent observation of cells generally suffers from the limited axial resolution due to elongated point spread function microscope optics. Consequently, three-dimensional imaging results in that is several times worse than transversal. The optical solutions this problem usually require complicated optics and extreme spatial stability. A straightforward way eliminate anisotropic fuse images recorded multiple viewing directions achieved mostly by mechanical rotation entire sample. In...

Measuring viscosity in volumes smaller than a microliter is challenging endeavor. A new type of microscopic viscometers presented to assess the Newtonian liquids. Micron-sized flexible polymer cantilevers are created by two-photon polymerization direct laser writing. Because low stiffness and high elasticity material microcantilevers exhibit pronounced Brownian motion when submerged liquid medium. By imaging cantilever's spherically shaped end, these fluctuations can be tracked with...

Abstract We combine two-photon lithography and optical tweezers to investigate the Brownian fluctuations propeller characteristics of a microfabricated helix. From analysis mean squared displacements time correlation functions we recover components full mobility tensor. find that motion displays correlations between angular translational from which can directly measure hydrodynamic coupling coefficient is responsible for thrust generation. By varying distance microhelices no-slip boundary...

We demonstrate the use of microfabricated supporting structures for maneuvering and polystyrene microspheres as magnifying lenses in imaging applications. The structure isolates trapping light from magnifier, hence avoiding direct radiation to sample being observed which could be damaging, especially biological specimens. Using an optical setup, we actuation a microsphere not held by traps, show possibility through such microspheres.