We present SoilTile, a novel ground sensing approach that explores soil as an interactive medium. Built upon the principles of Soil-based Microbial Fuel Cells (SMFCs), SoilTile draws on the natural electrochemical interactions between soil and embedded electrodes—not as a source of energy, but as a way to sense physical contact through electrical response. When pressure applied to the cathode, SMFC produce measurable variations in output voltage. Building on this phenomenon, we construct modular ground sensing units that detect localized pressure through a matrix of electrodes, structured to respond under human activities or object placement. With its minimalist structure, DIY-friendly fabrication, and potential for seamless integration into natural environments, SoilTile offers a simple, material-driven platform for designing interactive spaces.

1. SoilTile:
Soil-based Ground Sensing
01 Introduction
02 Sensing Principle
• When pressure is applied, the cathode compresses
into soil, changing the contact condition.
• This displaces air gaps and alters electrochemical
interactions, leading to voltage variation.
The ground is a ubiquitous and passive
interface that supports human activity.
Background
Existing floor sensing relies on
dense sensor arrays and complex
wiring, limiting scalability.
Problem
SoilTile leverages the electrochemical
behavior of SMFCs to sense contact
via voltage response.
Approach
03
• Each modular unit includes a shared anode and
a 2×2 grid of cathodes embedded in moist soil.
• A rubber sheet and replaceable top layer
(e.g., turf, cork) maintain voltage responsiveness.
04 Example Application
• Pressure from sitting,
standing, or placing objects
produces localized voltage
patterns.
• Voltage deltas (ΔV) across
cathodes visualize force
distribution without
calibration.
05 Future Work
• Evaluate spatial resolution and signal precision for
Human Activity Recognition (HAR).
• Explore outdoor deployment and long-term signal
stability under environmental changes.
• Integrate biodegradable materials to enhance
sustainability of embedded systems.
SoilTile Structure
Contact ： info-lcl-group@keio.jp
Yuma Tsukakoshi 1) , Tian Min1) , Annemarie Spiller2) , Chengshuo Xia3) , Anusha Withana 4) , Yuta Sugiura1)
1) Keio University, 2) Davis Senior High School, 3) Xidian University, 4) The University of Sydney