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Imagine a natural disaster scenario, such as an earthquake, that inflicts widespread damage to buildings and structures, critical utilities and infrastructure, and threatens human safety. Having the ability to navigate the rubble and enter highly unstable areas could prove invaluable to saving lives or detecting additional hazards among the wreckage.
Partnering rescue personnel with robots to evaluate high-risk scenarios and environments can help increase the likelihood of successful search and recovery efforts, or other critical tasks while minimizing the threat to human teams.
“Whether in a natural disaster scenario, a search and rescue mission, a hazardous environment, or other critical relief situation, robots have the potential to provide much needed aide and support,” said Dr. Ronald Polcawich, a DARPA program manager in the Microsystems Technology Office (MTO). “However, there are a number of environments that are inaccessible for larger robotic platforms. Smaller robotics systems could provide significant aide, but shrinking down these platforms requires significant advancement of the underlying technology.”
Miniaturized robotic systems that make use of micro technologies are termed as microrobots. A microrobot may also be defined as one that possesses traits of a robot in the macro world and has some form of reprogrammable behaviour and is capable of adapting, the only difference to a macrorobot being the scale at which they are placed.
The most challenging aspect in the development of microrobots is the fabrication of micro actuators and micro sensors which can give high efficiency and high stability. To overcome such problems scientists and researchers are combining technologies such as Micro/Nano Electro Mechanical Systems (MEMS, NEMS), nanotechnology and biotechnology.
To help overcome the challenges of creating extremely SWaP-constrained microrobotics, DARPA is launching a new program called SHort-Range Independent Microrobotic Platforms (SHRIMP).
“Micro-to-mm sized platforms provide a unique opportunity to push the development of highly efficient, versatile microelectronics,” said Polcawich. “While the goal of SHRIMP is to develop small-scale, independent robotics platforms, we anticipate that discoveries made through our actuator and power storage research could prove beneficial to a number of fields currently constrained by these technical challenges–from prosthetics to optical steering.”
Robot Olympics
Defence Advanced Research Agency (DARPA) is also planning to host Robot Olympics. The problem faced is that for the proposed event new and improved innovative robots would need to be either found or invented, and apparently, the robots would need to measure at just a fraction of an inch. These incredible robots would then be set to compete in tests of speed, agility, and strength, no different to the attributes put to the test in human Olympics.
One of the more interesting obstacles the bots will face is one in which the robot will test untethered actuator power systems. This is to see how high and how far the robots are able to jump, along with how much weight they can lift, how far they can throw objects and how they do in a tug of war. The throwing stands out as particularly intriguing, as this implies that they may have some sort of arms. Another category is designed for complete robot designs, in which the tiny bots will be evaluated on navigating an obstacle course, rock piling, climbing a vertical surface and performing in a biathlon. It is hoped the bots will be tested in March 2019.
Although the very small nature of these robots will limit them from doing many tasks that larger robots could perform, it will allow them to go places and perform specific tasks that larger robots are incapable of. It is safe to say that these robots will not be used solely for these Olympic games. “From prosthetics to optical steering,” says Ronald Polcawich, DARPA program manager in the Microsystems Technology Office. This is obviously just a tiny fraction of the possibilities but it should be noted that he chose these in particular, it may indicate future plans for DARPA if the Olympic games are successful for the robots. It in fact, would definitely not be very surprising if the bots were put to use in a military way.
SWaP-constrained microrobotics Technologies
The goal of SHRIMP is to develop and demonstrate multi-functional micro-to-milli robotic platforms for use in natural and critical disaster scenarios. To achieve this mission, SHRIMP will explore fundamental research in actuator materials and mechanisms as well as power storage components, both of which are necessary to create the strength, dexterity, and independence of functional microrobotics platforms.
Technological advances in additive manufacturing, piezoelectric actuators, and low-power sensors have allowed researchers to expand into the realm of micro-to-milli robotics. However, due to the technical obstacles experienced as the technology shrinks, these platforms lack the power, navigation, and control to accomplish complex tasks proficiently. In addition to advancing the state-of-the-art for actuator technology, SHRIMP seeks to develop highly efficient power storage devices and power conversion circuitry.
Actuators
Actuator technologies greatly affect a robotic platform’s mobility, load-bearing capacity, and dexterity, among other capabilities. Under the SHRIMP program, researchers will work to push beyond the current state-of-the-art and develop actuator materials and mechanisms that prioritize force generation, efficiency, strength-to-weight ratio, and maximum work density.
“The strength-to-weight ratio of an actuator influences both the load-bearing capability and endurance of a micro-robotic platform, while the maximum work density characterizes the capability of an actuator mechanism to perform high intensity tasks or operate over a desired duration,” said Polcawich. “Making significant advances to actuator mechanisms and materials will greatly impact our ability to develop micro-to-milli robotic platforms capable of performing complex tasks in the field.”
Power storage and power conversion
As size of the components reduces at the microscale so does the volume capacity of the battery, hence supplying on-board power to a microrobot is extremely challenging. Other than biocompatible and chemically powered designs, most microrobots are powered by off board sources. The power required by the microrobot depends upon the size of the robot and the operating environment. Sensors and micro tools can function at comparatively lesser power. The other major technique of power sourcing for the microrobot other than on-board storages is providing wireless power sources such as Radio Frequency, Optical Power, and even energy scavenging.
As SHRIMP aims to create complex micro-to-milli robots that operate independently, creating compact power sources and converters that can support high-voltage actuation mechanisms and significantly reduce battery drain becomes critical.
As yet, there are there are no complete micro- or milli-robotic systems able to perform complex jobs proficiently. Today, most micro- and milli-robots today rely on physical, optical, magnetic, or RF tethers to supply power, control, and processing which limits their utility.
As such, SHRIMP will explore fundamental research into power converters that can operate at frequencies of tens of Hz with exceptional efficiency as well as high energy density and high specific energy battery technologies.
“Micro-to-mm sized platforms provide a unique opportunity to push the development of highly efficient, versatile microelectronics,” said Polcawich. “While the goal of SHRIMP is develop small-scale, independent robotics platforms, we anticipate that discoveries made through our actuator and power storage research could prove beneficial to a number of fields currently constrained by these technical challenges–from prosthetics to optical steering.”
Engineering Challenges
While advancing actuator and power supply technology will help to significantly advance the field, they are only part of the challenge when it comes to developing micro-to-milli robotics. “Engineering for extreme SWaP minimization is a diverse task that must take these areas into account but also the mechanical, electrical, and thermal considerations required for designing a highly-functional microsystem,” said Polcawich.
Researchers will be further challenged to bring the fundamental research efforts together with engineering problem solving to develop and demonstrate multi-functional micro-to-milli scale robotics platforms that deliver untethered mobility, maneuverability, and dexterity.
The SHRIMP platforms will be evaluated using many of the same principles employed in the National Institute of Standards and Technology (NIST) Robotics Test Facility, which has been adapted for micro-to-milli robotic platforms. To determine potential field utility, each participating team will compete in an Olympic-style evaluation to test the platform’s mobility, maneuverability across flat and inclined surfaces, load-bearing capability, speed, and other capabilities.
DARPA SHRIMP awards
Officials of the U.S. Defense Advanced Research Projects Agency (DARPA) in Arlington, Va., have awarded two contracts for the SHort-Range Independent Microrobotic Platforms (SHRIMP) project. DARPA in March 2019 awarded a potential $3.6 million contract to Honeywell International Inc. Automation and Control Solutions (ACS) division in Golden Valley, Minn.; and a potential $1.3 million contract in Feb 2019 to Rutgers University in New Brunswick, N.J., for separate technology thrusts of the SHRIMP program.
Researchers at Honeywell and Rutgers will focus on developing fundamental actuator and power components for insect-scale robots, and will demonstrate them at a first responder robotics test facility at the U.S. National Institute of Standards and Technology (NIST). Actuator technologies for insect-scale-robotics must focus on force generation, efficiency, strength-to-weight ratio, and maximum work density.
Power storage and conversion will center on enabling insect-scale-robots to perform complex operations without power, control, or processing supplied by a tether. Actuators will focus on building mechanical moving parts for robot maneuverability, dexterity, and manipulation. Insect scale robotics until now has focused simply on moving, and such robots tend to be simple, possess limited intelligence, and lack the power, navigation, actuation, and control to accomplish tasks beyond this. DARPA’s contracts to Honeywell and Rutgers have base phases and options for second and third phases
Status
The SHort Range Independent Microrobotic Platforms (SHRIMP) program developed efficient and capable actuation mechanisms and power efficient voltage conversion circuits for microrobotic platforms. The primary technical focus areas were the efficiency, robustness, and force output of millimeter-scale actuators, and the power and energy capacity of batteries and chiplevel power converters. The program advanced the microrobotics field, allowing future robots to be realized in much smaller form factors than are previously possible.
