Electronic skin (E-skin) imitates human skin by converting external stimuli into electrical signals. E-skin requires high flexibility and a high level of device integration. Unlike conventional E-skin creation methods, a highly sensitive pressure sensor matrix (100 pixels cm −2 ) made of position-registered elastic conductive microparticles (MPs) is created. The MPs form a Schottky junction with the bottom electrode and the current through the junction is sensitive to external pressure, forming a simple one-selector two-terminal device array. The Schottky junction eliminates the electrical cross talks between the sensor pixels consisting of 64 MPs in each. The flexible pressure sensor matrix is used as an artificial fingertip for Braille reading and as an electronic scale based on detailed force distribution. This work opens up the possibility that assembled MPs, which have been a long-standing research topic in academia, can be used to make practical electronic devices.

A high‐resolution E‐skin matrix without electrical crosstalk between the pixels is manufactured by Jin Woong Kim, Unyong Jeong, and co‐workers in article number https://doi.org/10.1002/adfm.201801858. The diode‐based tactile sensor matrix uses a position‐registered conductive microparticles array and its Schottky junctions with a flexible hybrid electrode. This new, transistor‐free approach to E‐skin offers a flexible electronic balance and can finger read Braille.

Boston ivy (Parthenocissus tricuspidata) climbs brick walls using its tendril disks, which excrete a sticky substance to perform binding and attachment. While the cellular structures and adhesive substances involved have been identified for decades, their practical applicability as an adhesive has not yet been demonstrated. A Boston ivy disk‐inspired adhesive film patch system is reported in which structural and compositional features of the Boston ivy disk are mimicked with a form of thin adhesive film patches. In analogy to the sticky disk of a mature ivy in which porous microchannels are occupied by catechol‐containing microgranules on the bound site, 3,4‐dihydroxylphenylalanine bolaamphiphile nanoparticle (DOPA‐C7 NP)‐coated alginate microgels are two‐dimensionally positioned into the cylindrical holes that are periodically micropatterned on the flexible stencil film. Finally, it is demonstrated that the pressurization of the patch breaks the microgels filled in the holes, releasing the polysaccharides and leading to crosslinking with DOPA‐C7 NPs via ligandation with combined Ca2+ and Fe3+ ions, thus enabling development of a pressure‐mediated adhesion technology.

Embolization is a nonsurgical, minimally invasive procedure that deliberately blocks a blood vessel. Although several embolic particles have been commercialized, their much wider applications have been hampered owing mainly to particle size variation and uncontrollable degradation kinetics. Herein we introduce a microfluidic approach to fabricate highly monodisperse gelatin microparticles (GMPs) with a microshell structure. For this purpose, we fabricate uniform gelatin emulsion precursors using a microfluidic technique and consecutively cross-link them by inbound diffusion of glutaraldehyde from the oil continuous phase to the suspending gelatin precursor droplets. A model micromechanic study, carried out in an artificial blood vessel, demonstrates that the extraordinary degradation kinetics of the GMPs, which stems from the microshell structure, enables controlled rupturing while exhibiting drug release under temporary chemoembolic conditions.

A new platform for designing 2D colloidal arrays by using Janus microparticles (JMPs) with tunable anisotropic particle geometry is introduced. The JMPs are synthesized by the photopolymerization of biphasic emulsion droplets produced by capillary‐based microfluidics while adjusting the spreading coefficient between −4.4 and −7.2 mN m−1. The unidirectional rubbing of JMPs leads to their exact positioning in the stencil holes. The ratio of the hole diameter to the bigger bulb diameter of JMPs, ranging from 1.05–1.16, is critical for maximizing the positioning rate. When the anisotropic geometry factor is near zero, a standing particle configuration with a protrusion in the stencil hole is obtained more efficiently due mainly to the enhanced steric constraint. Finally, it is demonstrated that different types of JMPs with controlled sizes and geometries can be arrayed at specific hole sites of the stencil, thus enabling development of a colloidal pixel‐based micropatterning technology.