This paper describes the performance of a fluidic microrobot using Electrowetting on Dielectric (EWOD). A system to control the fluidic microrobot was designed, constructed and deployed in the NIST Mobile Microrobotics Challenge at ICRA 2011. The microrobots (0.1 M KCl and 550 μm diameter) demonstrated the ability to perform controlled maneuvers in 2-D while transporting hydrophilic objects. The EWOD system is composed of a DIP-mounted die produced via standard microfabrication techniques and containing the control electrodes / competition arena, and a transparent ITO cover slip for grounding. Key advantages of this platform include a scalable design for batch EWOD system fabrication, potential simultaneous control of multiple microrobots, and an easily portable, compact system design.

This paper presents the first results for jumping robots at millimeter size scales. Jumping at small sizes requires the quick release of stored energy to accelerate the robot to its takeoff velocity. Two approaches to this energy release are considered. The first is similar to the method used by most larger jumping robots and insects; energy is stored mechanically and generates thrust against the ground upon release. A new microfabrication process incorporates polymer springs for the robot leg and the resulting 4mm × 4mm × 0.3mm jumping mechanism has been launched over 32 cm into the air by hand. The second approach utilizes stored chemical energy and generates thrust by expelling gas from a chemical reaction. This energetic material has been combined with sensing, control, and power on a 4mm × 7mm × 4mm polymer chassis, and jumps in response to light stimuli have reached 8 cm in height.

The first MEMS process integrating soft elastomers in a standard silicon-on-insulator (SOI) wafer without assembly has been demonstrated for use in microrobotic mechanisms. This process allows silicon and poly(dimethylsiloxane) (PDMS) features to be defined in-plane with feature sizes down to 2 μm. Test structures have been used to characterize the Young's modulus of the resulting PDMS at 1.4 MPa along with adhesion to silicon structures. In addition, compliant flexures have been designed, fabricated and characterized for eventual use in microrobot legs. Test structures have been mechanically folded 180° out of plane over 60 times without failure.

Photo-patternable adhesives and silicones are introduced for use in centimeter-scale robotics. Traditional approaches to making robots at this size scale require the use of expensive start-up equipment and/or precise machining, and generally yield fragile and costly robots in small numbers. The multi-material milli-robot prototyping process uses Loctite® polymer products and photolithography to rapidly fabricate robust, inexpensive, and compliant robots only centimeters in size. In this paper, the process flow is described and characterized with minimum feature sizes of 0.25 mm in polymer layers 0.18 mm thick. Both commercial and ink-jet printed masks are used for the photolithography steps. Finally, a functional inchworm robot and a small gripper have been designed and demonstrated with Nitinol shape memory alloy (SMA) used for actuation. The gripper is 1.2 g and costs $3.21 in small numbers while the inchworm robot is 7.4 g and costs $7.76 in small numbers. Building a functional robot from a computer design takes less than 1 hour.