Gel-like Implant Destroys Pancreatic Cancer

Biomedical engineers at Duke University have demonstrated the most effective treatment for pancreatic cancer ever recorded in mouse models. While most mouse trials consider simply halting growth a success, the new treatment completely eliminated tumors in 80 percent of mice across several model types, including those considered the most difficult to treat.

The approach combines traditional chemotherapy drugs with a new method for irradiating the tumor. Rather than delivering radiation from an external beam that travels through healthy tissue, the treatment implants radioactive iodine-131 directly into the tumor within a gel-like depot that protects healthy tissue and is absorbed by the body after the radiation fades away.

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Artificial Muscle

Wearing a flower brooch that blooms before your eyes sounds like magic. KAIST researchers have made it real with robotic muscles. Researchers have developed an ultrathin, artificial muscle for soft robotics. The advancement, recently reported in the journal Science Robotics, was demonstrated with a robotic blooming flower brooch, dancing robotic butterflies and fluttering tree leaves on a kinetic art piece.


The robotic equivalent of a muscle that can move is called an actuator. The actuator expands, contracts or rotates like muscle fibers using a stimulus such as electricity. Engineers around the world are striving to develop more dynamic actuators that respond quickly, can bend without breaking, and are very durable. Soft, robotic muscles could have a wide variety of applications, from wearable electronics to advanced prosthetics.

The team from KAIST’s Creative Research Initiative Center for Functionally Antagonistic Nano-Engineering developed a very thin, responsive, flexible and durable artificial muscle. The actuator looks like a skinny strip of paper about an inch long. They used a particular type of material called MXene, which is class of compounds that have layers only a few atoms thick.

Their chosen MXene material (T3C2Tx) is made of thin layers of titanium and carbon compounds. It was not flexible by itself; sheets of material would flake off the actuator when bent in a loop. That changed when the MXene was “ionically cross-linked” — connected through an ionic bond — to a synthetic polymer. The combination of materials made the actuator flexible, while still maintaining strength and conductivity, which is critical for movements driven by electricity.

Their particular combination performed better than others reported. Their actuator responded very quickly to low voltage, and lasted for more than five hours moving continuously. To prove the tiny robotic muscle works actuator into wearable art: an origami-inspired brooch mimics how a narcissus, the team incorporated the flower unfolds its petals when a small amount of electricity is applied. They also designed robotic butterflies that move their wings up and down, and made the leaves of a tree sculpture flutter.

Wearable robotics and kinetic art demonstrate how robotic muscles can have fun and beautiful applications,” said Il-Kwon Oh, lead paper author and professor of mechanical engineering. “It also shows the enormous potential for small, artificial muscles for a variety of uses, such as haptic feedback systems and active biomedical devices.”


Tiny 4-Inch Wafer Holds One Million NanoRobots

Researchers have harnessed the latest nanofabrication techniques to create bug-shaped robots that are wirelessly powered, able to walk, able to survive harsh environments and tiny enough to be injected through an ordinary hypodermic needle.

When I was a kid, I remember looking in a microscope, and seeing all this crazy stuff going on. Now we’re building stuff that’s active at that size. We don’t just have to watch this world. You can actually play in it,” said Marc Miskin, who developed the nanofabrication techniques with his colleagues professors Itai Cohen and Paul McEuen and researcher Alejandro Cortese at Cornell University while Miskin was a postdoc in the laboratory for atomic and solid state physics there. In January, he became an assistant professor of electrical and systems engineering at the University of Pennsylvania.

Miskin will present his microscopic robot research on this week at the American Physical Society March Meeting in Boston. He will also participate in a press conference describing the work. Information for logging on to watch and ask questions remotely is included at the end of this news release.

Over the course of the past several years, Miskin and research colleagues developed a multistep nanofabrication technique that turns a 4-inch specialized silicon wafer into a million microscopic robots in just weeks. Each 70 micron long (about the width of a very thin human hair), the robots’ bodies are formed from a superthin rectangular skeleton of glass topped with a thin layer of silicon into which the researchers etch its electronics control components and either two or four silicon solar cells — the rudimentary equivalent of a brain and organs.

Robots are built massively in parallel using nanofabrication technology: each wafer holds 1 million machines

The really high-level explanation of how we make them is we’re taking technology developed by the semiconductor industry and using it to make tiny robots,” said Miskin.

Each of a robot’s four legs is formed from a bilayer of platinum and titanium (or alternately, graphene). The platinum is applied using atomic layer deposition. “It’s like painting with atoms,” said Miskin. The platinum-titanium layer is then cut into each robot’s four 100-atom-thick legs. “The legs are super strong,” he said. “Each robot carries a body that’s 1,000 times thicker and weighs roughly 8,000 times more than each leg.”

The researchers shine a laser on one of a robot’s solar cells to power it. This causes the platinum in the leg to expand, while the titanium remains rigid in turn, causing the limb to bend. The robot’s gait is generated because each solar cell causes the alternate contraction or relaxing of the front or back legs. The researchers first saw a robot’s leg move several days before Christmas 2017. “The leg just twitched a bit,” recalled Miskin. “But it was the first proof of concept — this is going to work!

Teams at Cornell and Pennsylvania are now at work on smart versions of the robots with on-board sensors, clocks and controllers. The current laser power source would limit the robot’s control to a fingernail-width into tissue. So Miskin is thinking about new energy sources, including ultrasound and magnetic fields, that would enable these robots to make incredible journeys in the human body for missions such as drug delivery or mapping the brain.

We found out you can inject them using a syringe and they survive — they’re still intact and functional — which is pretty cool,” he said.


Metallic Wood

Researchers at the School of Engineering and Applied Science, the University of Illinois at Urbana–Champaign, and the University of Cambridge have built a sheet of nickel with nanoscale pores that make it as strong as titanium, but four to five times lighter. The empty space of the pores, and the self-assembly process in which they’re made, make the porous metal akin to a natural material, such as wood. And just as the porosity of wood grain serves the biological function of transporting energy, the empty space in the researchers’ “metallic wood” could be infused with other materials. Infusing the scaffolding with anode and cathode materials would enable this metallic wood to serve double duty: a plane wing or prosthetic leg that’s also a battery. The study was led by James Pikul, assistant professor in the Department of Mechanical Engineering and Applied Mechanics at Penn Engineering.

Metallic wood foil on a plastic backing

The reason we call it metallic wood is not just its density, which is about that of wood, but its cellular nature,” Pikul says. “Cellular materials are porous; if you look at wood grain, that’s what you’re seeing—parts that are thick and dense and made to hold the structure, and parts that are porous and made to support biological functions, like transport to and from cells.

The study has been published in Nature Scientific Reports,