Tahmid Latif

Line following terrestrial insect biobots

The present day technology falls short in offering centimeter scale mobile robots that can function effectively under unknown and dynamic environmental conditions. Insects, on the other hand, exhibit an unmatched ability to navigate through a wide variety of environments and overcome perturbations by successfully maintaining control and stability. In this study, we use neural stimulation systems to wirelessly navigate cockroaches to follow lines to enable terrestrial insect biobots. We also propose a system-on-chip based ZigBee enabled wireless neurostimulation backpack system with on-board tissue-electrode bioelectrical coupling verification. Such a capability ensures an electrochemically safe stimulation and avoids irreversible damage to the interface which is often misinterpreted as habituation of the insect to the applied stimulation.

Sound Localization Sensors for Search and Rescue Biobots

Recent advances in neural engineering have enabled direct control of insect locomotion through neural and muscular stimulation. The resulting insect biobots, with a natural ability to crawl through small spaces, offer unique advantages over traditional synthetic robots. A cyberphysical network of such biobots could prove useful for search and rescue applications in uncertain disaster environments. We present a vision-based automated system for an objective assessment of biobotic navigation capability on Madagascar hissing cockroaches. We report the most precise control results obtained with insect biobots so far both manually and autonomously. We also demonstrate autonomous control capability where a low-power insect-mounted array of microphones was used to localize a sound source and guide the biobot toward it. Forming a wireless mobile sensor network with directional and omnidirectional microphones distributed within the structure of a rubble pile could be useful for both environmental mapping and localization of trapped survivors under the rubble.

Kinect-based system for automated control of terrestrial insect biobots

Centimeter scale mobile biobots offer unique advantages in uncertain environments. Our previous experimentation has demonstrated neural stimulation techniques in order to control the motion of Madagascar hissing cockroaches. These trials relied on stimulation by a human operator using a remote control. We have developed a Kinect-based system for computer operated automatic control of cockroaches. Using image processing techniques and a radio transmitter, this platform both detects the position of the roach biobot and sends stimulation commands to an implanted microcontroller-based receiver. The work presented here enables repeatable experimentation and allows precise quantification of the line following capabilities of the roach biobot. This system will help refine our model for the stimulation response of the insect and improve our ability to direct them in increasingly dynamic situations.

Towards fenceless boundaries for solar powered insect biobots

Demonstration of remote navigation with instrumented insects, such as the Madagascar Hissing Cockroach, Gromphadorhina portentosa, has enabled the concept of biobotic agents for search and rescue missions and environmental monitoring applications. The biobots can form the nodes of a mobile sensor network to be established, for example, in unknown and dynamic environments after natural disasters to pinpoint surviving victims. We demonstrate here, for the first time, the concept of an invisible fence for insect biobots with an ultimate goal of keeping insect biobots within a certain distance of each other or a base station to ensure a reliable wireless network. For extended mission durations, this fenceless boundary would also be used to guide insects towards light sources for autonomous solar charging of their on-board batteries.

Biobotic insect swarm based sensor networks for search and rescue

The potential benefits of distributed robotics systems in applications requiring situational awareness, such as search-and-rescue in emergency situations, are indisputable. The efficiency of such systems requires robotic agents capable of coping with uncertain and dynamic environmental conditions. For example, after an earthquake, a tremendous effort is spent for days to reach to surviving victims where robotic swarms or other distributed robotic systems might play a great role in achieving this faster. However, current technology falls short of offering centimeter scale mobile agents that can function effectively under such conditions. Insects, the inspiration of many robotic swarms, exhibit an unmatched ability to navigate through such environments while successfully maintaining control and stability. We have benefitted from recent developments in neural engineering and neuromuscular stimulation research to fuse the locomotory advantages of insects with the latest developments in wireless networking technologies to enable biobotic insect agents to function as search-and-rescue agents. Our research efforts towards this goal include development of biobot electronic backpack technologies, establishment of biobot tracking testbeds to evaluate locomotion control efficiency, investigation of biobotic control strategies with Gromphadorhina portentosa cockroaches and Manduca sexta moths, establishment of a localization and communication infrastructure, modeling and controlling collective motion by learning deterministic and stochastic motion models, topological motion modeling based on these models, and the development of a swarm robotic platform to be used as a testbed for our algorithms.

Characterization of RSS variability for biobot localization using 802.15.4 Radios

A cyber-physically organized swarm of insect biobots or biological robots can aid first responders in search-and-rescue scenarios after natural disasters or earthquakes by establishing an under-rubble sensor network. In such a network, the nodes are represented by the insect biobots equipped with electronic backpacks utilizing a system-on-chip. This application requires effective real-time localization of the mobile sensor nodes. Radio signal strength (RSS) is a measurement of the received signal power, and can be used in estimating the distance between two nodes, which then can help localize the biobotic sensor nodes in the future. This paper investigates RSS variability and its suitability for biobotic localization.

A wireless system for longitudinal assessment of tissue-electrode interface in biobots

Biobots are instrumented insects whose direction of movement can be controlled through strategic neural stimulation via implanted electrodes. Biobotic control has been reported to gradually degrade over time in the course of weeks. This can be attributed to changes in the tissue-electrode interface properties. The assessment of the interface would be possible using an equivalent circuit model derived from electrochemical impedance spectroscopy based characterization. We propose a wireless electronic backpack-based system for longitudinal impedance spectroscopic analysis for monitoring and subsequent analysis of the tissue-electrode interface in biobots.

Using liquid metal alloy (EGaIn) to electrochemically enhance SS stimulation electrodes for biobotic applications

Biobotics is an emerging and useful advent in the field of robotics which harnesses the mechanical power of live invertebrates and benefits from them as “working” animals. Most biobotic applications rely on neural or muscular stimulation through implanted electrodes for achieving direct control of their locomotory behavior. Degradation of stimulation efficiency is often noticed through extended usage, partly owing to incompatibility of implanted electrodes to the application. Our previous achievements in biobotics utilized commercially available stainless steel wires as stimulation electrodes due to its availability and lower cost. In this study, we look into the potential of using a liquid metal alloy, eutectic gallium-indium (EGaIn), as a means of enhancing properties of the stainless steel electrodes and its first time consideration as in vivo neurostimulation electrodes. We present in vitro analysis of the electrodes in terms of the electrolyte-electrode interface impedance and interface equivalent circuit model.

Biobotic motion and behavior analysis in response to directional neurostimulation

This paper presents preliminary results for motion behavior analysis of Madagascar hissing cockroach biobots subject to stochastic and periodic neurostimulation pulses corresponding to randomly applied right and left turn, and move forward commands. We present our experimental setup and propose an unguided search strategy based stimulation profile designed for exploration of unknown environments. We study a probabilistic motion model fitted to the trajectories of biobots, perturbed from their natural motion by the stimulation pulses. Furthermore, we provide a statistical assessment of the biobotic directional response to turn commands and its correlation with stimuli profile over time. This study paves the way towards reliable control for more realistic under-rubble search and rescue applications.

A study on motion mode identification for cyborg roaches

This paper demonstrates the ability to accurately detect the movement state of Madagascar hissing cockroaches equipped with a custom board containing a five degree of freedom inertial measurement unit. The cockroach moves freely through an unobstructed arena while wirelessly transmitting its accelerometer and gyroscope data. Multiple window sizes, features, and classifiers are assessed. An in-depth analysis of the classification results is performed to better understand the strengths and weaknesses of the classifier and feature set. The conclusions of this study show promise for future work on cockroach motion mode identification and localization.