Jeffrey Laut

Closed-loop control of zebrafish response using a bioinspired robotic-fish in a preference test

In this paper, we study the response of zebrafish to a robotic-fish whose morphology and colour pattern are inspired by zebrafish. Experiments are conducted in a three-chambered instrumented water tank where a robotic-fish is juxtaposed with an empty compartment, and the preference of live subjects is scored as the mean time spent in the vicinity of the tanks two lateral sides. The tail-beating of the robotic-fish is controlled in real-time based on feedback from fish motion to explore a spectrum of closed-loop systems, including proportional and integral controllers. Closed-loop control systems are complemented by open-loop strategies, wherein the tail-beat of the robotic-fish is independent of the fish motion. The preference space and the locomotory patterns of fish for each experimental condition are analysed and compared to understand the influence of real-time closed-loop control on zebrafish response. The results of this study show that zebrafish respond differently to the pattern of tail-beating motion executed by the robotic-fish. Specifically, the preference and behaviour of zebrafish depend on whether the robotic-fish tail-beating frequency is controlled as a function of fish motion and how such closed-loop control is implemented.

Dynamic Modeling of a Robotic Fish Propelled by a Compliant Tail

In this paper, a dynamic model for a robotic fish propelled by a tail with a flexible fin is presented. The robotic fish is composed of two links connected by an actuated joint; the frontal link is rigid and acts as the robotic fish body, while the rear link serves as the tail. The latter comprises a rigid element connected to a flexible caudal fin, whose underwater vibration is responsible for propulsion. The dynamics of the frontal link are described using Kirchhoffs equations of motion for rigid bodies in quiescent fluids. The tail vibration is modeled using Euler-Bernoulli beam theory and the effect of the encompassing fluid is described using the Morison equation. The thrust production is assessed from static thrust data in terms of the fin-tip displacement; other salient model parameters are estimated through a nonlinear least squares technique. The model is validated against experimental data on circular and S-shaped trajectories. The model can be used for simulation, prediction, design optimization, and control, as it allows for the description of the robots motion as a function of the unique input of the system, that is, the servomotor angle. Within the latter application, a heading control algorithm, in which the controller is tuned on the basis of the dynamic model, is presented.

Zebrafish (Danio rerio) responds to images animated by mathematical models of animal grouping.

Mathematical models of fish schooling offer powerful tools to understand and interpret fundamental aspects of social life, such as foraging, predator avoidance, and migration. Here, we study zebrafish (Danio rerio) response to computer-animated fish shoals whose motion is generated by a mathematical model of schooling. We use a dichotomous test wherein fish freely position themselves near static images of zebrafish shoals or images animated by the model whose parameters are systematically varied.

Development of a Mechatronics-Based Citizen Science Platform for Aquatic Environmental Monitoring

In this paper, we present the design and proof of concept of a low-cost, self-sustained mobile surface vehicle for environmental monitoring. The vehicle is equipped with water quality sensors and cameras for image acquisition and two thrusters allowing it to maneuver. The device is part of a citizen science system wherein volunteers help in the environmental recovery of polluted bodies of water by performing online research and classification tasks. While aiding in environmental recovery, the users become more proficient in wildlife classification and water quality assessment. Telemetry collected by the vehicle is wirelessly uploaded to a web-based interface allowing volunteers to access images, positioning information, and water quality sensor data. The citizen science system allows for the study of social networking and human-computer interaction based on user activity. Specifically, the platform can be utilized to experiment with different interfaces and social interactions in hypothesis-driven research on human-computer interactions.

Increasing Patient Engagement in Rehabilitation Exercises Using Computer-Based Citizen Science

Patient motivation is an important factor to consider when developing rehabilitation programs. Here, we explore the effectiveness of active participation in web-based citizen science activities as a means of increasing participant engagement in rehabilitation exercises, through the use of a low-cost haptic joystick interfaced with a laptop computer. Using the joystick, patients navigate a virtual environment representing the site of a citizen science project situated in a polluted canal. Participants are tasked with following a path on a laptop screen representing the canal. The experiment consists of two conditions: in one condition, a citizen science component where participants classify images from the canal is included; and in the other, the citizen science component is absent. Both conditions are tested on a group of young patients undergoing rehabilitation treatments and a group of healthy subjects. A survey administered at the end of both tasks reveals that participants prefer performing the scientific task, and are more likely to choose to repeat it, even at the cost of increasing the time of their rehabilitation exercise. Furthermore, performance indices based on data collected from the joystick indicate significant differences in the trajectories created by patients and healthy subjects, suggesting that the low-cost device can be used in a rehabilitation setting for gauging patient recovery.

Activating social strategies: Face-to-face interaction in technology-mediated citizen science.

The use of crowds in research activities by public and private organizations is growing under different forms. Citizen science is a popular means of engaging the general public in research activities led by professional scientists. By involving a large number of amateur scientists, citizen science enables distributed data collection and analysis on a scale that would be otherwise difficult and costly to achieve. While advancements in information technology in the past few decades have fostered the growth of citizen science through online participation, several projects continue to fail due to limited participation. Such web-based projects may isolate the citizen scientists from the researchers. By adopting the perspective of social strategy, we investigate within a measure-manipulate-measure experiment if motivations to participate in a citizen science project can be positively influenced by a face-to-face interaction with the scientists leading the project. Such an interaction provides the participants with the possibility of asking questions on the spot and obtaining a detailed explanation of the citizen science project, its scientific merit, and environmental relevance. Social and cultural factors that moderate the effect brought about by face-to-face interactions on the motivations are also dissected and analyzed. Our findings provide an exploratory insight into a means for motivating crowds to participate in online environmental monitoring projects, also offering possible selection criteria of target audience.

Gowanus Voyage: Where Mechatronics, Public Art, Community Members, and Environmental Science Meet [Focus on Education]

The scientific literacy of the public contributes to the acceptance of new scientific concepts, technologies, and methods that may influence society as a whole [1]. Thus, increasing the publics awareness and knowledge in science, technology, engineering, and math (STEM) fields is not only essential for benefiting the economy in the long term [2]-[4] but also for improving societys capacity to make informed political decisions on pressing issues that are often rather convoluted [5]. To this end, mechatronics based outreach in informal settings has been shown to be an effective means to acquaint the public with established technical concepts and ongoing research questions [6]-[10].

Bioinspiring an Interest in STEM

Attracting K-12 students to pursue careers in science, technology, engineering, and mathematics (STEM) is viewed as a critical element for benefiting both the economy and society. This paper describes an outreach program, conducted in a Brooklyn, NY, USA, public middle school, aimed at educating students in mechatronics, biology, and bioinspiration. The program is designed to foster student interest in STEM subjects, especially engineering-related concepts, by actively demonstrating their application in solving tangible real-world problems. It consists of a series of lectures and practical activities that culminate with a hands-on bioinspiration-based event at the New York Aquarium. Survey results show that students who participated in the program have a better understanding of the relationship between engineering and nature, demonstrate improved knowledge of select STEM topics, and are more interested in pursuing STEM careers.

Swimming Robots Have Scaling Laws, Too

Aquatic animals of vastly different size show a simple relationship between swimming speed and body kinematics. Swimming robots, whose morphology and gaits are inspired by those animals, are not an exception.

A natural user interface to integrate citizen science and physical exercise

Citizen science enables volunteers to contribute to scientific projects, where massive data collection and analysis are often required. Volunteers participate in citizen science activities online from their homes or in the field and are motivated by both intrinsic and extrinsic factors. Here, we investigated the possibility of integrating citizen science tasks within physical exercises envisaged as part of a potential rehabilitation therapy session. The citizen science activity entailed environmental mapping of a polluted body of water using a miniature instrumented boat, which was remotely controlled by the participants through their physical gesture tracked by a low-cost markerless motion capture system. Our findings demonstrate that the natural user interface offers an engaging and effective means for performing environmental monitoring tasks. At the same time, the citizen science activity increases the commitment of the participants, leading to a better motion performance, quantified through an array of objective indices. The study constitutes a first and necessary step toward rehabilitative treatments of the upper limb through citizen science and low-cost markerless optical systems.