One of the major challenges in modern robotics is controlling micromanipulation by active and adaptive materials. In the respiratory system, such actuation enables pathogen clearance by means of motile cilia. While various types of artificial cilia have been engineered recently, they often involve complex manufacturing protocols and focus on transporting liquids only. Here, soft magnetic carpets are created via an easy self‐assembly route based on the Rosensweig instability. These carpets can transport not only liquids but also solid objects that are larger and heavier than the artificial cilia, using a crowd‐surfing effect.This amphibious transportation is locally and reconfigurably tunable by simple micromagnets or advanced programmable magnetic fields with a high degree of spatial resolution. Two surprising cargo reversal effects are identified and modeled due to collective ciliary motion and nontrivial elastohydrodynamics. While the active carpets are generally applicable to integrated control systems for transport, mixing, and sorting, these effects can also be exploited for microfluidic viscosimetry and elastometry.

Conventional magnet manufacturing is a significant bottleneck in the development processes of products that use magnets, because every design adaption requires production steps with long lead times. Additive manufacturing of magnetic components delivers the opportunity to shift to agile and test-driven development in early prototyping stages, as well as new possibilities for complex designs. In an effort to simplify integration of magnetic components, the current work presents a method to directly print polymer-bonded hard magnets of arbitrary shape into thermoplastic parts by fused deposition modeling. This method was applied to an early prototype design of a rotary blood pump with magnetic bearing and magnetic drive coupling. Thermoplastics were compounded with 56 vol.% isotropic NdFeB powder to manufacture printable filament. With a powder loading of 56 vol.%, remanences of 350 mT and adequate mechanical flexibility for robust processability were achieved. This compound allowed us to print a prototype of a turbodynamic pump with integrated magnets in the impeller and housing in one piece on a low-cost, end-user 3D printer. Then, the magnetic components in the printed pump were fully magnetized in a pulsed Bitter coil. The pump impeller is driven by magnetic coupling to non-printed permanent magnets rotated by a brushless DC motor, resulting in a flow rate of 3 L/min at 1000 rpm. For the first time, an application of combined multi-material and magnet printing by fused deposition modeling was shown. The presented process significantly simplifies the prototyping of products that use magnets, such as rotary blood pumps, and opens the door for more complex and innovative designs. It will also help postpone the shift to conventional manufacturing methods to later phases of the development process.

Transparent crystals comprising the nitrogen‐rich co­ordination unit [Pt(NH2trz)4]2+ were synthesized with counterions of various sizes but of the same charge (–1), yielding the compounds [Pt(NH2trz)4]Cl2·2H2O, [Pt(NH2trz)4](NO3)2 and [Pt(NH2trz)4](CF3SO3)2, with NH2trz designating 4‐amino‐1,2,4‐triazole. Single‐crystal X‐ray diffraction analysis showed that NH2trz coordinates with only the nitrogen atom in 1‐position in all compounds. The [Pt(NH2trz)4]2+ units are stacked such that the platinum atoms form linear arrays with Pt–Pt spacings mostly uncorrelated to anion size. The compound with the smallest anion (Cl–) has the smallest Pt–Pt spacing (4.72 Å) and shows a quasi‐one‐dimensional structure. Thermal decomposition of the compounds was observed around 200 °C. Electrical conductivity of [Pt(NH2trz)4]Cl2 and [Pt(NH2trz)4](SO3CF3)2 was investigated and found to be humidity‐dependent. Finally, [Pt(NH2trz)4]2+ ions obtained by dissolution of the chloride salt are shown to be useful for the synthesis of new compounds such as the Magnus' salt derivative [Pt(NH2trz)4][PtCl4].

Soft actuators have opened compelling new opportunities in the fields of manufacturing, robotics, and medicine. [1] Because of their conformal and mechanically compliant nature, actuators made of soft materials allow for safe interactions of robots with humans and provide an attractive platform to interface flexible electronics with human skin and tissues. [2][3][4][5] Potential applications that can benefit from these features include robots for manipulation of delicate objects, [6] exoskeletons for motion rehabilitation, medical prostheses, [7] surgical aid devices, [8,9] and intelligent reconfigurable matter in general. [10] In many of these applications, it is desirable to minimize the energy required for actuation, enhance actuation speed, and enable untethered autonomous motion.Among the several possible types of devices and actuation modes, [11][12][13][14][15][16][17][18][19][20] magnetically responsive actuators are particularly interesting, because they are fast, contactless, and are driven by magnetic fields that can be safely used in humans. [21] Contactless control allows for the manipulation of untethered devices in confined spaces, which is crucial for minimally invasive medical devices. [22] Making soft objects magneto-responsive is also a promising approach in the ongoing efforts to create devices with complex output motion driven by a simple single input. [23] For example, recent research has shown that the soft objects with tunable local magnetization patterns can undergo complex motions, such as crawling, rolling, and jumping when activated with an external magnetic field. These magneto-responsive soft materials have so far been produced in simple planar geometries using NdFeB microparticles that are pre-magnetized using magnetic fields higher than 1 T. [19,24,25] Although the magnetization of NdFeB particles using these approaches prevents de-magnetization of the actuator, the