This EArly-concept Grant for Exploratory Research (EAGER) Signals in the Soil (SitS) award funds a high risk/high return bio-inspired research project needed for the development of self-boring sensor probes in the ground. Distributed sensing is essential for realizing intelligent assessment or management of the natural and built environment based on rich spatial and temporal data. A wireless sensing network (WSN) is particularly attractive since it eliminates costly and cumbersome wire connections. However, there are tremendous challenges involved in the application of WSN in harsh environments such as the near-surface underground region, mainly due to the fact that soil is opaque, heterogeneous, dissipative and hard to penetrate/excavate. This EAGER project explores a bioinspired platform technology known as active self-boring robots, which will enable next generation dynamic underground WSN (DUWSN). In such a network, the sensor nodes are integrated into a robot, mimicking burrowing animals, that deploys itself autonomously with minimal disturbance to the soil and minimal human intervention. Thanks to its motility, each robot would be able to return to the surface for service purposes. More importantly, these robotic nodes would be able to locomote underground and change their sensing locations as needed. In this way, a dynamic reconfigurable rather than a static wireless sensing network can be established to improve spatial coverage and the resolution of the data as well as the reliability of the data transmission. The proposed research is potentially transformative since small, agile underground robots can be deployed for a wide range of direct applications. Examples include precision agriculture, contaminant monitoring and prediction, and health monitoring for infrastructure such as levees, dams and foundations. This platform technology can also be used for surveillance, reconnaissance and exploration purposes. This award allows the research team to actively reach out to researchers in related fields and explore broader collaborations, as well as to seek industrial partners to expedite the development and application of the proposed technology. Outreach and educational activities are planned to engage underrepresented first-generation undergraduate and high school students, in collaboration with the NSF Engineering Research Center for Biomediated and Bioinspired Geotechnics at Arizona State University.
This project will advance our understanding of underground locomotion via a robotic, self-boring platform purpose-built to explore soil/agent interactions. It will answer exploratory questions such as: 1) What are the mechanical requirements for a penetrating agent to achieve motility? 2) How do we mimic the self-boring mechanisms adopted by various burrowing animals? 3) To mimic a certain boring mechanism, which actuating and control strategy is best? and 4) Which self-boring mechanism is optimal for a certain type of soil such as sand, silt and clay? The search of solutions will start by examining a wide array of biological exemplars. An array of robot prototypes based on different self-boring mechanisms and actuating strategies will be designed. A fast prototyping strategy will be established to systematically design and fabricate the robots and will be informed by analytical and numerical modeling. The penetration performance of the robots with controlled kinematics and soil conditions will be characterized using an experimental testbed. And finally, relationships will be established to correlate control input, robot kinematics, soil properties and penetration performance, possibly aided by machine learning.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
