I n this article, we present the design, development, and characterization of a biomimetic robotic fish remotely controlled by an iDevice application (app) for use in informal science education. By leveraging robots, biomimicry, and iDevices, we seek to establish an engaging and unique experience for free-choice learners visiting aquariums, zoos, museums, and other public venues. The robotic fish incorporates a three-degree-of-freedom tail along with a combined pitch and buoyancy control system, allowing for high maneuverability in an underwater three-dimensional (3-D) space. The iDevice app implements three modes of control that offer a vividly colored, intuitive, and user-friendly theme to enhance the user experience when controlling the biomimetic robotic fish. In particular, the implemented modes vary in the degree of autonomy of the robotic fish, from fully autonomous to remotely controlled. A series of tests are conducted to assess the performance of the robotic fish and the interactive control modes. Finally, a usability study on elementary school students is performed to learn about students' perception of the platform and the various control modes. Robotic Fish ExhibitsTechnology facilitates learning and expression in both academic and nonacademic environments [1], [2]. In particular, the use of robotics in university-level classes and museums has been shown to effectively excite and educate students and free-choice learners [3], [4]. In the context of underwater robotics, various robotic fish have been developed and displayed for the entertainment and education of the general public in exhibits at aquariums [5], expositions [6], and water gardens [7]. Although these robots have generated considerable interest from onlookers, none of the exhibits offered opportunities for people to directly interact with the robotic fish.Interactivity in exhibits is a crucial part of science learning in informal settings, whereby interactive components are recognized to improve subject retention and enhance both sociability and curiosity in participants [8], [9]. To this end, smart devices have become increasingly popular as a tool for enhancing education through the use of interactive applications [10], [11]. Young participants have been shown to prefer the use of smart devices over traditional mediums, and better educational outcomes are attained with this growing technology [12]. To actively engage participants, museums, galleries,

Abstract-Much of robotics research is carried out using either PICs and processors that are a decade or more out of date The alternative is custom built electronics that is expensive and/or must be reinvented every time a new project is begun. The XBC is a new design for a robot controller merging a modern ARM processor with an FPGA that allows high performance -especially in vision processing and motor control -for a cost similar to controllers with a fraction of its capabilities. Additionally, the XBC uses a new, and still free, software development system, already in wide use. The XBC is being mass produced (at least in research hardware terms) so it is readily available and does not require computer hardware or electronics skills in order to be obtained. This paper describes the system, its capabilities and some potential applications.Index Terms-robot controller, back-emf, color tracking, robot programming environment I. THE XBC/IC SYSTEM For the past half-century, Moore's law has described how general purpose computing has risen in capability while the cost has declined. Along with those changes, advances in operating systems, graphics and user interfaces have lowered the technical barrier for entry to the point where more households in the US have computers than do not [2].However, this has not been the trend for robotics in the hobbyist and research market. As general purpose machines have advanced, their ability to interface to the physical world in a straightforward manner has often declined. While the number of embedded processors has skyrocketed in recent years [12], the equipment, software and required knowledge for entry into using those processors has also skyrocketed. The robot controllers powering most homebrew robots ten years ago (the Basic STAMP [3] and the Handy Board [7]) are still the controllers for many robots today, and have been displaced in numbers only by the RCX [9] -which while easy to use, has fewer practical capabilities than the systems it displaces.The XBC/IC system (see Figure 1) is an easy to use lowcost general purpose robot controller. The system provides powerful hardware (an FPGA linked to a commodity ARM processor) combined with the easy to use and very popular Interactive C programming environment. The resulting system has vision, control and interface capabilities that far exceed previous robot controllers for this market. The XBC uses Interactive C, the easy to use C programming environment already used by tens of thousands of robotics * This work was supported in part by the KISS Institute for Practical Robotics researchers, students and hobbyists. Together, the XBC and IC allow easy entry into advanced robotics applications. II. THE XBC HARDWAREThe XBC's unique hardware uses a Gameboy Advance (GBA) as the main processor. We chose the GBA because of its powerful industry-standard ARM processor, integrated TFT color display, low cost and widespread availability.The GBA also adds a certain "fun" element to an educational robotics platform. The XBC employs custom robot...