Our cricket micro-robot is being developed by an interdisciplinary team of faculty and students as part of the DARPA Distributed Robotics (DR) program. A "microrobot" is no larger than 5 cm in any dimension. Our robot will locomote by both walking and jumping and its design is based upon crickets.

A prototype of the rear leg of the robot was constructed. The joints are actuated by McKibben Pneumatic Artificial Muscles. It has been demonstrated that the two link prototype can operate in the coordinated manner and in through a large enough range of motion that is needed for locomotion. By powerfully kicking, the prototype has also demonstrated that it can generate the force needed for jumping.

Since the actuation of the cricket micro-robot will be pneumatic, it is necessary for a micropump to be located on board. The micropump is powered by a 5mm Smoovy motor. The gear head has a 1:25 transmission ratio. The microcompressor uses MEMS check valves and will need to supply 35psi for the robot to walk and jump.

From right to left are the spring, actuator and orifice plate for the MEMS Valves that will be used to distribute air from the air compressor to each of the actuators.

The three components will be placed into a package similar to the one that currently houses the micropump check valves.

The Continuous-Time Recurrent Neural Network (CTRNN) that will control the microrobot will be implemented in hardware using analog VLSI (aVLSI). aVLSI has been chosen because of its small circuit size, low power, and inherent neural network corollaries. The aVLSI will be fully programmable using non-volatile floating gate memories to store the CTRNN parameters. A test network that consists of a 2x2 CTRNN configured as an oscillator has been fabricated using the standard AMI 1.2mm ABN CMOS process available through MOSIS. Also, the interfaces to connect the CTRNN to the Joint-Angle Sensors (JASs) and MicroElectroMechanical Valves (MEMVs) that sense and actuate the legs of the microrobot, respectively, have been fabricated. Tunneling junctions that will provide the programming and erasing mechanisms for the non-volatile memories have been fabricated as well and demonstrate Fowler-Nordheim (FN) Tunneling in a standard process. All circuits are shown in the above picture, and the IC itself is 2mm square.

Feedback from the legs of the robot to the controller will occur through MEMS Joint Angle Sensors (JAS) being developed at Carnegie Mellon University. The controller will be able to know the exact position of each joint by reading the voltage from this sensor. The cilia can be retracted to prevent damage during jumping.

A small single-legged hopper was designed and built to demonstrate autonomy. Several different components were tested on this robot that will eventually be used on the cricket microrobot. Those components include the powerplant and the controller. The hopper is statically and passively dynamically stable, fits into a cube that is 2" on a side, and is fully autonomous.