Last Wednesday, I attended AeroVironment’s presentation of its contribution to NASA’s Mars Helicopter mission. The autonomous vertical-lift drone is remarkably capable of flying through the planet’s thin atmosphere, as demonstrated on Earth in a vacuum chamber by AeroVironment CEO Wahid Nawabi.
The drone will provide a bird’s-eye view of the Martian landscape to guide the growing fleet of terrestrial rovers through the hazardous terrain. The Mars Helicopter project is a culmination of decades of unmanned aerial leadership by the avionics contractor.
Tucked in the corner of AeroVironment’s briefing was its smallest military unmanned aerial system (UAS), Switchblade. The lethal nature of this backpack-sized drone is remarkable as it is a disposal device capable of precision strikes (aka targeted assassinations). According to Nawabi, Switchblade is the ultimate “warfighter” that promises “minimal collateral effects,” for beyond line-of-sight reconnaissance missions. In addition to offensive munitions, it provides a powerful sensor payload to enable intelligence gathering and surveillance of the targets prior to impact.
AeroVironment’s website boasts, “This miniature, remotely-piloted or autonomous platform can either glide or propel itself via quiet electric propulsion, providing real-time GPS coordinates and video for information gathering, targeting, or feature/object recognition. The vehicle’s small size and quiet motor make it difficult to detect, recognize and track even at very close range.” While Nawabi assured me Switchblade’s protocol requires a human in the loop, I left the meeting feeling queasy at the prospect of a stealthy autonomous killing machine.
Single-use robots for search and rescue
But the idea of single-use robots is gaining traction beyond military applications. Researchers at the The University of California, Berkeley are building inexpensive mini-robots for search and rescue missions. Dr. Ronald Fearing explains, “Living in earthquake country in California. It’s frustrating to know people will be trapped after a building collapse. We have an indeterminate amount of time to find someone before they may die. Small robots would allow us to get in and communicate fairly quickly.”
Inspired by insects, Fearing’s lab has been creating biomimetic machines capable of amazing speed and maneuverability. Partnered with the National Science Foundation, Fearing’s group set out to build a swarm of crawling robots that resemble the indomitable cockroach, in size, gait and dynamics.
Using low-cost materials, laser printers and origami folds, Fearing’s team built two prototype versions: a 3 centimeter miniRoACH (RObotic Autonomous Crawling Hexapod), and a 10 centimeter VelociRoACH, The larger version is one of the fastest robots of its size, sprinting 11 miles per hour or 10 times faster than a typical cockroach. Fearing has designed its disposable robots as a network of skills that work in unison to problem solve and report on ground conditions.
Using an analogy, Fearing describes, “If you think about people, if you send a single person to explore and they encounter a 12-foot high fence, they are stuck. But if you send two people, the first can boost the second one up, and then the second can pull the first one up.”
Fearing’s lab observed how ants collaborate by stepping onto one another to accomplish tasks. The researchers followed suit by outfitting VelociRoACH’es with sensors, tethers and winches to enable each robotic crawler to pull and mount the other to overcome obstacles. A huge benefit of this collaborative platform is its cost effectiveness, as “simple robots are $10 to $100 each instead of $1,000” said Fearing.
Controlling the colonies of mechanical roaches that number between 50-100 at each deployment means humans provide the general directions to the group while the individual robots coordinate among themselves via radio. Fearing imagines that eventually his mini-robots will work in tandem with a a bigger robot with more computing power, this “mother ship” will monitor the mission of hundreds of bots in the field.
To date, the Berkeley lab is already work with California Task Force 3 Urban Search and Rescue to help them locate trapped people in collapsed buildings. Fearing aims to outfit first responders with a backpack of robots managed through a simple tablet that is easily deployed in emergency situations. The team is also working on small disposable robots for industrial settings to detect chemical leaks at refineries and reactors. “When it’s dirty and dangerous, it’s good to use small, disposable mobile robots,” says Fearing.
3D-printed smart gel
While Fearing’s low-cost robots work with metal components, this week at Rutgers University Dr. Howan Lee of the Department of Mechanical and Aerospace Engineering illustrated how 3D printed soft materials could be manipulated with ordinary water. “Our 3D-printed smart gel has great potential in biomedical engineering because it resembles tissues in the human body that also contain lots of water and are very soft. It can be used for many different types of underwater devices that mimic aquatic life like the octopus,” elucidates Lee.
In his demonstration, Lee applied an electrical field to his water-based gel to illustrate how it can grab objects underwater. According to the research the applications for this technology could range from underwater inspections to developing next generation medical devices. In particular the US Navy is potentially interested in utilizing such technology for single use clandestine operations by mimicking underwater animals. As Lee exclaims, “If you have full control of the shape, then you can program its function. I think that’s the power of 3D printing of shape-shifting material. You can apply this principle almost everywhere.”
To prove the versatility of his new application, Lee built at 10 millimeter stick figure out of his hydrogel and applied an electrical charge to make it walk. The whimsical creation danced on screen without any tether, tubing, or connected wires. Lee expounded that his research is unlike any other in soft robotics.
“They [soft robots] usually require tubing to supply the required air pressure and associated valves and control systems. Also, it is quite challenging to miniaturized these soft robots to micro-scale. Our 3D-printed hydrogel actuators are driven by material deformation, which is controlled by remotely applied electric field, allowing for untethered actuation.”
Lee declares that robot octopuses are just the beginning, “We believe that 3D printing of EAH [Electro Active Hydrogels] with precise dimensional control could unlock otherwise untapped potential of EAH and may lead to various applications in soft robots, artificial muscles, and tissue engineering.” The sheer depth of single use robots illustrates how quickly the industry is moving from space to insects to, now, living tissues.