Scientists turn to tiny creatures for bio-inspired Soldier systems
December 13, 2010
U.S. Army Research Laboratory scientists are looking to some of nature's smallest creatures - those that crawl, climb and fly - for inspiration in developing next-generation technology for complex Soldier systems.
The gecko, mantis shrimp and even pesky houseflies are among the tiniest creatures ARL scientists are investigating to better understand and design the controls necessary for Micro-autonomous Systems Technology (MAST) scaled platforms to fly and hover by themselves through complex environments, especially inside buildings and though wind.
These bio-inspired research projects are part of the Laboratory's MAST Collaborative Technology Alliance, a consortium of ARL and industry and academic partners that performs research to enhance warfighters' tactical situational awareness in urban and complex terrain by enabling the autonomous operation of a collaborative ensemble of multifunctional, mobile microsystems.
"Autonomous micro-robotics offers 'leap ahead' technology that will ultimately provide the Soldier with substantially enhanced situational awareness," explained Dr. William D. Nothwang, material scientist and ARL lead for the MAST-Microelectronics Center within ARL's Sensors and Electron Devices Directorate. "Currently, it requires many Soldiers to control a robot and provide overwatch protection to the Soldier controlling the robot. Autonomous robotics offer the potential to flip that Soldier to robot ratio from many Soldiers to one robot into many robots to one Soldier"
ARL's in-house sensors research team performs basic research to address the many fundamental challenges associated in making tiny technology a reality. Collaborative research efforts between the Army and some of the nation's leading university research departments have led to the development of integrated antennas on MAST scaled platforms, radio repeaters for autonomous deployment of sensor and communications networks, and a 35 gram mini-quad rotor autonomous platform.
But one of the most aggressive projects to date is work on haltere, tiny pendulums growing beneath the wings houseflies that help them maintain stability as they fly. Haltere, which flap up and down just as the wings do and act as an insect's balancing and guidance system, help them perform fast aerobatics.
The Army wants to create insect-inspired microflight in small, robotic platforms that will work autonomously and collaboratively with Soldiers in searching buildings and caves, and transmitting information gathered with on-board sensors from the most dangerous environments through novel communications networks.
The eventual goal is to create a swarm of these microsystems - each with a specific role to capture video, record sound and sense chemical agents - then share the information and send it back to the command center, or a Soldier, as one unified message, Nothwang said.
"There are two problems with the traditional approaches to measure angular gate like roll, pitch and yaw," he noted. "First, there are traditional approaches that work. But, to minimize the error rate, navigation grade gyroscopes and angular rate sensors are very large, bulk and power hungry. Maintaining the performance of nav-grade sensors at the extremely small sale is incredibly challenging.
"Secondly, there have been previous attempts to fabricate and design haltere at the meso-scale, or less than a centimeter in length, that have successfully detected angular rate. However, there is an incredibly complex milieu of forces acting upon the rotating body. It becomes increasingly difficult to de-convolute the myriad forces in a time frame that allows for the device to be used as a control sensor."
ARL is overcoming these challenges by moving from the meso scale to the micro-scale. "It is possible to isolate the sensor from some of the extraneous forces, such as wind shear, acting on the sensor," Nothwang said.
"Secondly, it is necessary to add a filtering mechanism directly into the sensor system to isolate the forces of interest. The first steps in this have been accomplished with mechanical logic structures that passively filter and isolate the different wave component. But, there is still substantial work to do in this area, before the haltere sensor systems are viable."
ARL's work builds upon findings from some of the first studies on the haltere at Harvard and California Institute of Technology to move the design into the microscale.
"We have learned from those earlier studies on how to better isolate the wave components," added Nothwang. "We have incorporated different sensing mechanisms that should enable more enhanced sensitivity, and we have enabled direct integration with electronics to substantially reduce the overall size, weight and power requirements."