The mechanical features of biological muscles are difficult to reproduce completely in synthetic systems. A new class of soft pneumatic structures (vacuum‐actuated muscle‐inspired pneumatic structures) is described that combines actuation by negative pressure (vacuum), with cooperative buckling of beams fabricated in a slab of elastomer, to achieve motion and demonstrate many features that are similar to that of mammalian muscle.

Motion 3Historically, many machines (especially robots) were designed to mimic the motions of humans and other animals, but to add power, speed, "endurance," and reproducibility to those motions. [1] The robots on industrial assembly lines, for example, extend the capabilities of the workers that originally carried out assembly by hand using simple tools, by adding power, complex tools, indifference to environmental conditions, and mechanical "endurance". Similarly, four-wheeled robots are loosely derived from fourlimbed animals, and aerial drones can be traced in design backwards in time through manned aircraft, to birds. Conventional machines-especially those fabricated from metal, ceramics, and structural polymers (so-called "hard" machines)-can carry out almost arbitrarily complex motions using pulleys, cables, gears, and electric or hydraulic actuators. To achieve controlled motion, however, they also normally require complex systems for active controls (networks of sensors, actuators, and feedback controllers). [2,3] Some of these "hard" systems are exquisitely and highly developed, but can be heavy, energy inefficient, dangerous to humans, and expensive.We are exploring soft actuators and robots-machines modeled after simpler animals (e.g., starfish, worms, and squid) having no hard internal or external structures, and fabricated entirely or predominantly in soft, compliant polymers. [4,5] The first generation of these systems-originally sketched by Suzumori, [6][7][8] and then realized and elaborated by us, [5,[9][10][11][12][13] and by others [4] -use pneumatic actuators, comprising networks of micro-channels; in our systems, differential expansion of these pneumatic networks (PneuNets) by pressurization using air produces motions (especially bending, curling, and variants on them) that are already established as useful in grippers, and interesting for their potential in walkers, tentacles, and a number of other soft, actuated systems. [14] 4 Although the design of the first of these systems has been relatively simple, the motion they produce on actuation can be surprisingly sophisticated: for example, a representative structure-the "finger" or "tentacle" of a gripper-curls non-uniformly, starting from its tip and proceeding to its stem, although the pressure applied in the PneuNet is approximately uniform throughout the system of inflatable channels. [10,11] This motion reflects a non-linear property of soft materials and structures, referred to as a "snapthrough instability". [15][16][17][18][19] Although nonlinear properties of materials are often considered a disadvantage, this type of non-linearity, illustrated by snap-through, and other complex mechanical characteristics of soft systems, are proving to be useful, and to offer new capabilities to effectors, machines, and robots, because they enable a range of motions of sufficient complexity that-although they might be possible to replicate in a hard robotic system [20] -it would be complicated and expensive to do so. This paper demonstrates the ut...

There is a pressing need to develop nanoplatforms that integrate multimodal therapeutics to improve treatment responses and prolong the survival of patients with unresectable hepatocellular carcinoma (HCC). Mesoporous silica-coated gold nanomaterials have emerged as a novel multifunctional platform combining tunable surface plasmon resonance and mesoporous properties that exhibit multimodality properties in cancer theranostics. However, their reduced radiation-absorption efficiency and limited surface area hinder their further radiochemotherapeutic applications. To address these issues, we designed Janus-structured gold-mesoporous silica nanoparticles using a modified sol-gel method. This multifunctional theranostic nanoplatform was subsequently modified via the conjugation of folic acid for enhanced HCC targeting and internalization. The loaded anticancer agent doxorubicin can be released from the mesopores in a pH-responsive manner, facilitating selective and safe chemotherapy. Additionally, the combination of chemotherapy and radiotherapy induced synergistic anticancer effects in vitro and exhibited remarkable inhibition of tumor growth in vivo along with significantly reduced systematic toxicity. Additionally, the Janus NPs acted as targeted computed tomography (CT)-imaging agents for HCC diagnosis. Given their better performance in chemoradiotherapy and CT imaging as compared with that of their core-shell counterparts, this new nanoplatform designed with dual functionalities provides a promising strategy for unresectable HCC theranostics.

No abstract

Stimuli-triggered nanoplatforms have become attractive candidates for combined strategies for advanced liver cancer treatment. In this study, we designed a light-responsive nanoplatform with folic acid-targeting properties to surmount the poor aqueous stability and photostability of indocyanine green (ICG). In this Janus nanostructure, ICG was released on-demand from mesoporous silica compartments in response to near-infrared (NIR) irradiation, exhibiting predominant properties to convert light to heat in the cytoplasm to kill liver cancer cells. Importantly, the silver ions released from the silver compartment that were triggered by light could induce efficient chemotherapy to supplement photothermal therapy. Under NIR irradiation, ICG-loaded Janus nanoplatforms exhibited synergistic therapeutic capabilities both in vitro and in vivo compared with free ICG and ICG-loaded mesoporous silica nanoparticles themselves. Hence, our Janus nanoplatform could integrate ICG-based photothermal therapy and silver ion-based chemotherapy in a cascade manner, which might provide an efficient and safe strategy for combined liver cancer therapy.

No abstract

This paper describes several noncontact methods of orienting objects in 3D space using Magnetic Levitation (MagLev). The methods use two permanent magnets arranged coaxially with like poles facing and a container containing a paramagnetic liquid in which the objects are suspended. Absent external forcing, objects levitating in the device adopt predictable static orientations; the orientation depends on the shape and distribution of mass within the objects. The orientation of objects of uniform density in the MagLev device shows a sharp geometry-dependent transition: an analytical theory rationalizes this transition and predicts the orientation of objects in the MagLev device. Manipulation of the orientation of the levitating objects in space is achieved in two ways: (i) by rotating and/or translating the MagLev device while the objects are suspended in the paramagnetic solution between the magnets; (ii) by moving a small external magnet close to the levitating objects while keeping the device stationary. Unlike mechanical agitation or robotic selection, orienting using MagLev is possible for objects having a range of different physical characteristics (e.g., different shapes, sizes, and mechanical properties from hard polymers to gels and fluids). MagLev thus has the potential to be useful for sorting and positioning components in 3D space, orienting objects for assembly, constructing noncontact devices, and assembling objects composed of soft materials such as hydrogels, elastomers, and jammed granular media.eveloping new techniques to manipulate and orient components is part of the developing field of advanced manufacturing. Procedures for orienting hard objects reliably in three dimensions (3D) are essential for many existing manufacturing processes and relevant to a range of applications in other areas (1). Examples include operating automated manufacturing lines, sorting and prepositioning components for assembly, and inspecting parts for quality control. Components in assembly lines often have random orientations, and they must be oriented properly before assembly (2-4). Advanced and "next-generation" approaches based on biomimetic (5-8) and soft robotic (9) strategies, and hierarchically organized, self-assembled, and stimulus-responsive materials (10-15) particularly require methods capable of orienting and assembling soft, sticky, and easily damaged materials. Few methods exist to manipulate these types of materials without damaging them.One way of orienting hard objects is to agitate them mechanically, and to allow them to fit (or fall) into openings of complementary shape (2); for appropriate geometries, a correct fit ensures that the object is appropriately oriented and can be transported to the next process. The disadvantages of this method are that it can be slow, and that it is not suitable for objects that are soft, fragile, or sticky. Most importantly, it is only reliable for objects of anisotropic shape: that is, it fails for objects that have only slightly asymmetrical shapes or sizes (16,17)....

It is well known that the calcium ion is essential for maintaining life activities in living organisms, and it is of great significance to detect the intracellular calcium concentration. For the detection of calcium ions, we developed a new type of fluorescent carbon dots (CDs), whose surface was modified by ethylenebis­(oxyethylenenitrilo)­tetraacetic acid (EGTA) through a secondary hydrothermal method. This is a simple and convenient chemical preparation method because all reactions are carried out in the same autoclave, and the final product is directly the EGTA-modified CDs. The CDs exhibit bright blue fluorescence, and as the calcium concentration increases, the fluorescence intensity drops sharply. The fluorescence quenching correlates with the concentration of calcium ions and has a good linearity in the range of 15–300 μM with a detection limit of 0.38 μM. The experimental results confirmed that the detection of calcium ions by CDs is a static fluorescence quenching process. Also, cytotoxicity test and cellular imaging experiments have shown that the CDs are nontoxic and biocompatible.