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Miniature soft actuators have garnered attention across healthcare, military, and industrial fields; however, soft actuators mostly have functions and applications in nature‐inspired biomimetic locomotion, without any specific approaches reported for biomedical applications. In biomedical applications, soft actuators must be biodegradable, biocompatible, and visible in vivo. This study presents a multifunctional soft actuator comprising chitosan and magnetic nanoparticles (MNPs) fabricated via facile casting and laser micromachining. The actuator demonstrates programmable shape morphing and responds swiftly to six stimuli: humidity, chemical solvents, near‐infrared (NIR) light, radio‐frequency (RF) heating, temperature, and magnetic fields. This actuator shows feasibility for biomimetic applications, such as flower, leaf, larva, and finger. Furthermore, the actuator demonstrates magnetic locomotion, real‐time X‐ray visibility, biocompatibility, and biodegradability both in vitro and in vivo. The multistimulus‐responsive shape‐morphing performance of the soft actuator has potential as a wireless miniature robot in various fields, including biomimetic and biomedical applications. [ABSTRACT FROM AUTHOR]

Capsule endoscopy is a valuable tool for diagnosis of the gastrointestinal tract. As a result, active‐control capsule endoscopy, which can be controlled via external stimulation, has emerged as a prominent diagnosis tool, unlike traditional passive capsule endoscopy. However, owing to its rigid cover, the high rotating radii limit its observation range at anchor points, such as polyps. There are also persistent challenges with pass‐through in narrow spaces in the intestines. This study proposes a soft‐shell capsule endoscope (SSCE) to improve this limitation. Experiments ranging from virtual phantoms to ex vivo investigations in the stomach, small intestine, and large intestine were conducted to ensure comprehensive coverage of the entire digestive system by the SSCE. Additionally, in the stomach and intestine experiments, we compared the performances of the SSCE and hard‐shell capsule endoscope (HSCE) to highlight the advantages of the SSCE. The results demonstrate that the SSCE achieves a 37.3% increase in the observable angles through bending motions at the anchor point compared to the HSCE, in addition to increased efficiency of pass‐through in the intestines. This revolutionary innovation is expected to significantly impact and promote high efficiency via pass‐through and the observation area in the clinical application of capsule endoscopy. [ABSTRACT FROM AUTHOR]

Magnetic microscaffolds capable of targeted cell delivery have been developed for tissue regeneration. However, the microscaffolds developed so far with similar morphologies have limitations for applications to osteochondral disease, which requires simultaneous treatment of the cartilage and subchondral bone. This study proposes magnetically actuated microscaffolds tailored to the cartilage and subchondral bone for osteochondral tissue regeneration, named magnetically actuated microscaffolds for cartilage regeneration (MAM-CR) and for subchondral bone regeneration (MAM-SBR). The morphologies of the microscaffolds were controlled using a double emulsion and microfluidic flow. In addition, due to their different sizes, MAM-CR and MAM-SBR have different magnetizations because of the different amounts of magnetic nanoparticles attached to their surfaces. In terms of biocompatibility, both microscaffolds were shown to grow cells without toxicity as potential cell carriers. In magnetic actuation tests of the microscaffolds, the relatively larger MAM-SBR moved faster than the MAM-CR under the same magnetic field strength. In a feasibility test, the magnetic targeting of the microscaffolds in 3D knee cartilage phantoms showed that the MAM-SBR and MAM-CR were sequentially moved to the target sites. Thus, the proposed magnetically actuated microscaffolds provide noninvasive treatment for osteochondral tissue disease. [ABSTRACT FROM AUTHOR]

• Ecofriendly soft actuator based on cellulose acetate, graphene nanopowders, ionic liquid as plasticizer, and PEDOT:PSS as soft electrode. • Proposed membrane exhibited increments in specific capacitance and Young's modulus compare with a pure cellulose acetate actuator. • Proposed actuator showed a 2.9 times larger bending deformation and a 4.8 times faster response than those of pure cellulose acetate actuator. Ionic-type artificial muscles with eco-friendly, biodegradable, and biocompatible functionalities have attracted attention for a wide range of potential applications in wearable electronics, soft haptic-feedback systems, and active biomedical devices. Here, we report on the development of an ecofriendly high-performance ionic soft actuator based on biofriendly cellulose acetate (CA), graphene nanopowders (GN), ionic liquid (IL) as a plasticizer, and biofriendly-flexible-nonmetallic conducting polymer poly(3,4-ethylene-dioxythiopene)-polystyrenesulfonate (PEDOT: PSS) as an electrode, thereby realizing a novel ecofriendly CA-IL-GN actuator with a large bending mechanical deformation and a fast response time. The proposed CA-IL-GN (0.2 wt%) nanocomposite membrane exhibited dramatic increments in specific capacitance (2.92 times) and Young's modulus (2.38 times), thus leading to a 2.9 times larger bending deformation and a 4.8 times faster response than those of pure CA-IL actuator. Therefore, the developed ecofriendly high-performance CA-IL-GN actuator can be considered to be a promising candidate for human-friendly electronics, including artificial muscles, flexible haptic devices, soft wearable devices, and bio-medical devices, due to its cost-effectiveness, large bending mechanical actuation, fast response, and bio-friendly functionalities. [ABSTRACT FROM AUTHOR]