Lifeboat Foundation

Artificial muscles will power the soft robots and wearable devices of the future. But more needs to be understood about the underlying mechanics of these powerful structures in order to design and build new devices.

Now, researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have uncovered some of the fundamental physical properties of artificial muscle fibers.

“Thin soft filaments that can easily stretch, bend, twist or shear are capable of extreme deformations that lead to knot-like, braid-like or loop-like structures that can store or release energy easily,” said L. Mahadevan, the Lola England de Valpine Professor of Applied Mathematics, of Organismic and Evolutionary Biology, and of Physics. “This has been exploited by a number of experimental groups recently to create prototypical artificial muscle fibers. But how the topology, geometry and mechanics of these slender fibers come together during this process was not completely clear. Our study explains the theoretical principles underlying these shape transformations, and sheds light on the underlying design principles.”

This wearable gill could help you breathe underwater.

Advances in the fields of soft robotics, wearable technologies, and human/machine interfaces require a new class of stretchable materials that can change shape adaptively while relying only on portable electronics for power. Researchers at Carnegie Mellon University have developed such a material that exhibits a unique combination of high electrical and thermal conductivity with actuation capabilities that are unlike any other soft composite.

In findings published in Proceedings of the National Academy of Sciences this week, the researchers report on this intelligent new material that can adapt its shape in response to its environment. The paper is titled “A multifunctional shape-morphing elastomer with liquid metal inclusions.”

“It is not only thermally and electrically conductive, it is also intelligent,” said Carmel Majidi, an associate professor of mechanical engineering who directs the Soft Machines Lab at Carnegie Mellon. “Just like a human recoils when touching something hot or sharp, the material senses, processes, and responds to its environment without any external hardware. Because it has neural-like electrical pathways, it is one step closer to artificial nervous tissue.”

Evening gowns with interwoven LEDs may look extravagant, but the light sources need a constant power supply from devices that are as well wearable, durable, and lightweight. Chinese scientists have manufactured fibrous electrodes for wearable devices that are flexible and excel by their high energy density. Key for the preparation of the electrode material was a microfluidic technology, as shown in the journal Angewandte Chemie.

Dresses emitting sparkling light from hundreds of small LEDs may create eye-catching effects in ballrooms or on fashion shows. But wearable electronics can also mean sensors integrated in functional textiles to monitor, for example, water evaporation or temperature changes. Energy storage systems powering such wearable devices must combine deformability with high capacity and durability. However, deformable electrodes often fail in long-term operation, and their capacity lags behind that of other state-of-the-art energy storage devices.

Electrode materials usually benefit from a fine balance of porosity, conductivity, and electrochemical activity. Material scientists Su Chen, Guan Wu, and their teams from Nanjing Tech University, China, have looked deeper into the material demands for flexible electrodes and developed a porous hybrid material synthesized from two carbon nanomaterials and a metal-organic framework. The nanocarbons provided the large surface area and excellent electrical conductivity, and the metal-organic framework gave the porous structure and the electrochemical activity.

Steve Mann invented a precursor to Google Glass in the 1990s—which he now uses almost 24/7. But “the father of wearable computing” has an ominous warning about where technology is taking us next.

A professor at the University of Chicago believes he is on his way to creating a wearable for market that will manipulate your muscles with electrical impulses to cause you to move involuntarily so you can perform a physical task you otherwise didn’t know how to do, like playing a musical instrument or operating machinery.

Dr. Pedro Lopes, who heads the Human Computer Integration lab at the university, is all about integrating humans and computers, closing the gap between human and machine. His team, which focuses on engineering the next generation of wearable and haptic devices, is exploring the endless possibilities if wearables could intentionally share parts of our body for input and output, allowing computers to be more directly interwoven in our bodily senses and actuators.

Lopes’ vision: a wearable EMS device that would look like a sleeve and be able to send electrical impulses in the right timing and in the right fashion to make a user’s muscles move involuntarily to perform a physical task. EMS stands for electrical muscle stimulation.

A small clinical trial, announced by U.S. company NeuroEM Therapeutics, shows reversal of cognitive impairment in Alzheimer’s disease patients after just two months of treatment using a wearable head device. Electromagnetic waves emitted by the device appear to penetrate the brain to break up amyloid-beta and tau deposits.

The need to make some hardware systems tinier and tinier and others bigger and bigger has been driving innovations in electronics for a long time. The former can be seen in the progression from laptops to smartphones to smart watches to hearables and other “invisible” electronics. The latter defines today’s commercial data centers—megawatt-devouring monsters that fill purpose-built warehouses around the world. Interestingly, the same technology is limiting progress in both arenas, though for different reasons.

The culprit, we contend, is the printed circuit board. And the solution is to get rid of it.

Our research shows that the printed circuit board could be replaced with the same material that makes up the chips that are attached to it, namely silicon. Such a move would lead to smaller, lighter-weight systems for wearables and other size-constrained gadgets, and also to incredibly powerful high-performance computers that would pack dozens of servers’ worth of computing capability onto a dinner-plate-size wafer of silicon.

Combining new classes of nanomembrane electrodes with flexible electronics and a deep learning algorithm could help disabled people wirelessly control an electric wheelchair, interact with a computer or operate a small robotic vehicle without donning a bulky hair-electrode cap or contending with wires.

By providing a fully portable, wireless brain-machine interface (BMI), the wearable system could offer an improvement over conventional electroencephalography (EEG) for measuring signals from visually evoked potentials in the human brain. The system’s ability to measure EEG signals for BMI has been evaluated with six human subjects, but has not been studied with disabled individuals.

The project, conducted by researchers from the Georgia Institute of Technology, University of Kent and Wichita State University, was reported on September 11 in the journal Nature Machine Intelligence.