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We move thanks to coordination among many skeletal muscle fibers, all twitching and pulling in sync. While some muscles align in one direction, others form intricate patterns, helping parts of the body move in multiple ways.

In recent years, scientists and engineers have looked to muscles as potential actuators for “biohybrid” robots—machines powered by soft, artificially grown . Such bio-bots could squirm and wiggle through spaces where traditional machines cannot. For the most part, however, researchers have only been able to fabricate artificial muscle that pulls in one direction, limiting any robot’s range of motion.

Now MIT engineers have developed a method to grow artificial muscle tissue that twitches and flexes in multiple coordinated directions. As a demonstration, they grew an artificial, muscle-powered structure that pulls both concentrically and radially, much like how the iris in the human eye acts to dilate and constrict the pupil.

The device provides a range of sensations, such as vibrations, pressure, and twisting. A team of engineers led by Northwestern University has developed a new wearable device that stimulates the skin to deliver a range of complex sensations. This thin, flexible device gently adheres to the skin, offering more realistic and immersive sensory experiences. While it is well-suited for gaming and virtual reality (VR), the researchers also see potential applications in healthcare. For instance, the device could help individuals with visual impairments “feel” their surroundings or provide feedback to those with prosthetic limbs.

00:00 Intro.
00:20 José Delgado’s beginnings with BCIs.
00:42 Use of BCI to reduce aggression.
00:57 How the brain and nerve cells work.
03:00 Stimulation of brain areas (motor cortex)
03:51 How Utah arrays works!
05:16 Measurement of voltage peaks (spikes)
06:06 How the Neuralink N1 works!
08:20 How the Stentrode by Synchron works!
09:40 The future of exoskeletons.
09:53 Are we becoming machines ourselves?

We all encounter gels in daily life – from the soft, sticky substances you put in your hair, to the jelly-like components in various foodstuffs. While human skin shares gel-like characteristics, it has unique qualities that are very hard to replicate. It combines high stiffness with flexibility, and it has remarkable self-healing capabilities, often healing completely within 24 hours after injury.

Until now, artificial gels have either managed to replicate this high stiffness or natural skin’s self-healing properties, but not both. Now, a team of researchers from Aalto University and the University of Bayreuth are the first to develop a hydrogel with a unique structure that overcomes earlier limitations, opening the door to applications such as drug delivery, wound healing, soft robotics sensors and artificial skin.

In the breakthrough study, the researchers added exceptionally large and ultra-thin specific clay nanosheets to hydrogels, which are typically soft and squishy. The result is a highly ordered structure with densely entangled polymers between nanosheets, not only improving the mechanical properties of the hydrogel but also allowing the material to self-heal.

Twenty-four stroke patients have already used the complete system, consisting of an exoskeleton for the arm and shoulder in combination with FES as part of the ReHyb research project. Half of them were patients at the Schön Klinik Bad Aibling Harthausen, which is leading the study. The researchers also used a computer game that automatically adapts to the individual player’s capabilities. It trains them to grip and move their arms shortly after a stroke by reacting to colored balls flying toward them at varying speeds on a screen. The task is to catch the balls and match them with color-coded boxes.

At the center of TUM Professor Sandra Hirche’s setup is a digital twin that records the individual requirements of each patient and places them in a control loop. Among other things, the researchers have to determine how well each patient can move their arm and hand. In the event of a stroke, for example, paralysis can be caused by damage to the motor area in the brain responsible for movement. However, it is impossible to predict how severely the signals transmitted from the brain to the muscles in the forearm will be impaired after the stroke. “Individual muscle strands in the forearm can be stimulated to the right extent for hands and fingers to move,” says Prof. Hirche, who holds the Chair of Information-Oriented Control at TUM. In addition to information on muscle activity in the forearm, the researchers need to know how strongly the muscles should be stimulated in conjunction with the exoskeleton assistance.

Empa researchers are working on artificial muscles that can keep up with the real thing. They have now developed a method of producing the soft and elastic, yet powerful structures using 3D printing. One day, these could be used in medicine or robotics – and anywhere else where things need to move at the touch of a button.


A team of researchers from Empa’s Laboratory for Functional Polymers is working on actuators made of soft materials. Now, for the first time, they have developed a method for producing such complex components using a 3D printer. The so-called dielectric elastic actuators (DEA) consist of two different silicone-based materials: a conductive electrode material and a non-conductive dielectric. These materials interlock in layers. “It’s a bit like interlacing your fingers,” explains Empa researcher Patrick Danner. If an electrical voltage is applied to the electrodes, the actuator contracts like a muscle. When the voltage is switched off, it relaxes to its original position.

3D printing such a structure is not trivial, Danner knows. Despite their very different electrical properties, the two soft materials should behave very similarly during the printing process. They should not mix but must still hold together in the finished actuator. The printed “muscles” must be as soft as possible so that an electrical stimulus can cause the required deformation. Added to this are the requirements that all 3D printable materials must fulfill: They must liquefy under pressure so that they can be extruded out of the printer nozzle. Immediately thereafter, however, they should be viscous enough to retain the printed shape. “These properties are often in direct contradiction,” says Danner. “If you optimize one of them, three others change … usually for the worse.”

Mind Control: Past and Future https://www.hks.harvard.edu/sites/default/files/2025-01/24_Meier_02.pdf


On Jan. 28, 2024, Noland Arbaugh became the first person to receive a brain chip implant from Neuralink, the neurotechnology company owned by Elon Musk. The implant seemed to work: Arbaugh, who is paralyzed, learned to control a computer mouse with his mind and even to play online chess.

The device is part of a class of therapeutics, (BCIs), that show promise for helping people with disabilities control prosthetic limbs, operate a computer, or translate their thoughts directly into speech. Current use of the technology is limited, but with millions of global cases of spinal cord injuries, strokes, and other conditions, some estimates put the market for BCIs at around $400 billion in the U.S. alone.

A new discussion paper from the Carr Center for Human Rights welcomes the potential benefits but offers a note of caution drawn from the past, detailing unsettling parallels between an era of new therapies and one of America’s darkest chapters: experiments into psychological manipulation and mind control.

Empa researchers are working on producing artificial muscles that can keep up with the real thing. They have now developed a method of producing the soft and elastic yet powerful structures using 3D printing.

One day, these could be used in medicine or robotics—and anywhere else where things need to move at the touch of a button. The work is published in the journal Advanced Materials Technologies.

Artificial muscles don’t just get robots moving: One day, they could support people at work or when walking, or replace injured muscle tissue. However, developing artificial muscles that can compare to the real thing is a major technical challenge.