Elastomer polydimethylsiloxane (PDMS) films with embedded in-plane gradient stress are created by making PDMS/(PDMS + silicone oil) crosslinked bilayers and extracting the oil in a suitable organic solvent bath. The collapse of the elastomer after oil extraction generates differential stress in the films that is manifested through their out-of-plane deformation. The curvature κ of narrow stripes of the bilayer, which is composed of layers of approximately equal thicknesses and elasticity moduli, is satisfactorily described by the simple relationship κ = 1.5δH(-1), where δ is the mechanical strain, and H is the total thickness of the bilayer. Curvature mapping of triangular PDMS plates reveals the existence of spherical and cylindrical types of deformation at different locations of the plates. Various 3D-shaped objects can be formed by the self-folding of appropriately designed 2D patterns that are cut from the films, or by nonuniform distribution of the collapsing layer. Thin PDMS bilayers with embedded stress roll up into microtubes of almost perfect cylindrical shape when released in a controlled manner from a substrate.

Self assembled catheters with deep sub-mm diameters deliver liquids, carry out micromanipulation, and sense magnetic fields.

Analytical platforms based on impedance spectroscopy are promising for non‐invasive and label‐free analysis of single cells as well as of their extracellular matrix, being essential to understand cell function in the presence of certain diseases. Here, an innovative rolled‐up impedimetric microfulidic sensor, called sensor‐in‐a‐tube, is introduced for the simultaneous analysis of single human monocytes CD14+ and their extracellular medium upon liposaccharides (LPS)‐mediated activation. In particular, rolled‐up platinum microelectrodes are integrated within for the static and dynamic (in‐flow) detection of cells and their surrounding medium (containing expressed cytokines) over an excitation frequency range from 102 to 5 × 106 Hz. The correspondence between cell activation stages and the electrical properties of the cell surrounding medium have been detected by electrical impedance spectroscopy in dynamic mode without employing electrode surface functionalization or labeling. The designed sensor‐in‐a‐tube platform is shown as a sensitive and reliable tool for precise single cell analysis toward immune‐deficient diseases diagnosis.

We propose a microfluidics device whose main functional part consists of a microcapillary produced by the self-rolling of a thin poly(dimethylsiloxane) film. Rolling is caused by inhomogeneous swelling of the film, pre-treated by oxygen plasma, in the vapour of chloroform. The capillaries are integrated with external electrical circuits by co-rolling electrodes and micro-resistors. The local control of temperature in the tubes by Joule heating is illustrated via the rate of an intra-tubular chemiluminescent reaction. The novel tubes with engineered inner structure can find numerous advanced applications such as functional elements of integrated microfluidics circuits.

Several attempts are made to downscale nuclear magnetic resonance (NMR) spectroscopy systems and to enable high resolution chemical analysis of small sample quantities. However, miniaturization is nontrivial due to stringent demands on precise analyte sampling within the detector while performing local excitation of the sample and signal detection with a microsized coil. Imperfect coil geometry and inhomogeneities in the coil's surrounding environment have a detrimental impact on the signal quality, hampering further development of miniature NMR systems. To solve this challenge, a new type of monolithic wafer‐scale self‐assembled microcoils with a detection volume of 1.5 nL are integrated into a microfluidics circuit. The microcoils are fully encapsulated in polydimethylsiloxane (PDMS) allowing for simplified and precise supply of an analyte through the interior of the detector. Due to their construction, with the inner winding touching the analyte, the microcoils have an almost 100% filling factor. Magnetic field inhomogeneities are reduced through well‐defined microtubular architectures and susceptibility matched conductors. This approach results in a spectral linewidth of only 8 ppb with shimming and 22 ppb without shimming. The demonstrated methodology promotes the realization of next generation miniaturized analytical NMR systems for product monitoring, safety verification, medical testing, and material evaluation.