MEMS-Based Multi Gas Sensor Module for Early Detection of Battery Thermal Runaway in Humanoid Robots

1. Overview

The Multi Gas Sensor Module is a compact, low-power MEMS-based gas and temperature sensor module designed to detect early signs of thermal runaway in lithium battery packs. It is optimized for integration into the confined battery compartments of humanoid robots where weight, size, and reliability are crucial.

2. Key Features

• Multi-factor sensing: H2, CO, and temperature

• High sensitivity to early-stage gas release from lithium batteries

• UART or I2C digital communication interface

• Automatic baseline correction and configurable storage mode

• Small size suitable for embedded integration (SMD or terminal plug)

• Low power: Max. 66mW @ 3.3VDC

• Wide range: 0-5000 ppm for H2 and CO, -20 to 100°C for temperature

3. Application Scenario: Humanoid Robots

Humanoid robots contain compact and high-density battery systems. Due to the complexity of movement and AI processing, continuous high-power demand increases the risk of battery overheating. Our module offers early gas detection (before temperature spike), enabling pre-emptive safety responses:

• Location: Place the module near battery cell clusters or near top/venting locations in the battery chamber

• Quantity: One module per battery pack or per heat-prone zone

• Advantage: Detects gas signal 2-5 minutes earlier than temperature sensors alone

Purpose in Battery Packs
In lithium-ion battery systems, when a cell overheats or fails, it can release gases such as:

Carbon monoxide (CO)

Carbon dioxide (CO₂)

Hydrocarbons or organic solvent vapors

The MEMS-based gas sensor module detects these gases in real time, providing a critical early warning before thermal runaway leads to fire, explosion, or other system failures.

Objective
To monitor the lithium-ion battery pack inside a humanoid robot for early signs of failure—especially thermal runaway, which can lead to fire or explosion.

How It Works

1. Thermal or Electrical Stress in Battery
During intense robotic activity (walking, running, or heavy lifting), the battery experiences high current draw.

Overcharging, cell aging, or mechanical stress may cause overheating or internal short circuits.

2. Early Gas Emission
Before visible smoke or fire occurs, a failing Li-ion cell releases small amounts of gases such as:

CO (carbon monoxide)

H2 (Hydrogen)

Hydrocarbons or solvent vapors

These gases are early indicators of thermal runaway.

3. Gas Detection by MEMS Sensor Module
A MEMS-based gas sensor, placed near the battery pack or inside the torso/battery bay of the robot, detects the gas concentration increase.

These sensors are:

Ultra-small (ideal for space-constrained robots)

Fast in response

Low in power consumption

4. Signal Processing and Safety Action
The sensor sends data to the robot’s battery management system (BMS) or main MCU via I²C, UART, or analog interface.

If a threshold is crossed, the system can:

Shut down power to prevent fire

Trigger an alert or safe pose (robot freezes, sits, or shuts down)

Notify remote monitoring or send a log for predictive maintenance

Typical Deployment in Robot
Placement: Near battery cells or along heat flow paths inside the robot's torso or leg segments

Interface: Connected to robot’s embedded controller or safety module