A new ultrasound-guided 3D printing technique could make it possible to fabricate medical implants in vivo and deliver tailored therapies to tissues deep inside the body – all without invasive surgery, researchers report. 3D bioprinting technologies offer significant promise to modern medicine by enabling the creation of customized implants, intricate medical devices, and engineered tissues tailored to individual patients. However, most current approaches require invasive surgical implantation. Although in vivo bioprinting – “3D printing” tissue directly within the body – offers a less invasive alternative, it has been limited by challenges like poor tissue penetration depth, a narrow range of biocompatible bioinks, and the need for printing systems that operate at high resolution with precise, real-time control. To address these barriers, Elham Davoodi and colleagues developed a novel imaging-guided platform called Imaging-Guided Deep Tissue In Vivo Sound Printing (DISP), which uses focused ultrasound and ultrasound-responsive bioinks to precisely fabricate biomaterials directly within the body. These bioinks, or US-inks, combine biopolymers, imaging contrast agents, and temperature-sensitive liposomes carrying crosslinking agents and can be delivered to targeted tissue sites deep within the body via injection or catheter. A focused ultrasound transducer, guided by automated positioning and a predefined digital blueprint, triggers localized low-temperature heating (slightly above body temperature) that releases the crosslinker, initiating immediate in situ gel formation. Moreover, the bioinks and their resulting gels can be tailored for various functions, including conductivity, localized drug delivery, and tissue adhesion, as well as real-time imaging capabilities. Davoodi et al. validated DISP by successfully printing drug-loaded and functional biomaterials near cancerous sites in a mouse bladder and deep within rabbit muscle tissue, demonstrating potential applications for drug delivery, tissue regeneration, and bioelectronics. Further biocompatibility tests revealed no signs of tissue damage or inflammation, and the body cleared unpolymerized US-ink within a week, illustrating the platform's safety. “Although Davoodi et al. advanced ultrasound 3D printing toward clinical translation, additional refinements are needed to implement the technology for clinical use,” writes Xiao Kuang in a related Perspective. “A detailed relationship between process conditions, the structure of the printed material, and the resulting properties must be elucidated through careful testing.”

Using only airflow and simple physical design – resulting in a structure that looks like a roadside “inflatable tube dancer” – researchers have developed soft robots that achieve coordinated, autonomous movement without relying on complex electronic controllers. In nature, animals often move with remarkable efficiency. They do this by seamlessly integrating the nervous system, body mechanics, and environmental interactions. This decentralized coordination allows animals to move efficiently without relying on constant direction from the brain. In contrast, most robots depend heavily on centralized processors to orchestrate their movements. While rigid and soft robots can exploit body dynamics or shape changes to move and avoid obstacles, many remain limited in adaptability due to a lack of limbs or reliance on slow, sequential control mechanisms. Moreover, their bulky, analog-like design introduces energy inefficiencies and slow response times, limiting their practicality and autonomous capabilities in complex environments. To achieve rapid movement without relying on a central processor, Alberto Comoretto and colleagues developed a self-oscillating robotic limb powered only by a continuous stream of air. The limb consists of a bent silicone tube, which – without airflow – remains in stable, kinked positions. However, when steady airflow is introduced, it spontaneously oscillates between kinked states, performing rapid stepping motions at frequencies reaching 300 hertz. This motion arises from a feedback loop between pressure, kink formation, and tube resistance – akin to a mechanical “heartbeat.” By physically linking multiple limbs and exploiting environmental feedback, Comoretto et al. achieved synchronized gaits without any electronic control, enabling the robots to move at speeds exceeding those of comparable soft robots. They could also amphibiously enter and move in water through an automatic change in gait. For interested reporters, the authors have provided a number of videos illustrating the robotic platform’s capabilities.

Robots developed at MIT can now learn about an object’s weight, softness, or contents by picking it up and gently shaking it. A robot can accurately guess parameters like an object’s mass in a matter of seconds, without the need for cameras or other external sensors.

In a recent study published in the Plant Biotechnology Journal, researchers showed that some spinach defensins can confer similar protection to citrus and potatoes — and possibly other crops. The effects show significant progress toward recovering yield and improving quality in diseased plants.

In a recent study, Kim and co-author Woodam Chung, PhD, a forest engineer at Oregon State University, were the first to objectively measure biomechanical stress experienced by professional timber fellers during actual timber felling operations. They also evaluated forest workers’ perceptions of wearable exoskeletons—emerging technology already being used in other physically demanding industries such as shipbuilding and automotive and aerospace manufacturing.

Large language models (LLMs) are artificial intelligence (AI) systems that can understand and generate human language by analyzing and processing large amounts of text. In a new essay, a Carnegie Mellon University researcher critiques an article on LLMs and provides a nuanced look at the models’ limits for analyzing sensitive discourse, such as hate speech. The commentary is published in the Journal of Multicultural Discourses.