MEMS Sensor Contamination Detection via Thermal Compensation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for detecting contamination of micro-electromechanical sensors are inadequate, as they fail to accurately differentiate between clean and contaminated sensors based on temperature changes.

Innovation Solution

A method utilizing a heater and a temperature sensor arranged at a distance from the micro-electromechanical sensor, where thermal energy is used to heat the sensor, and the temperature and sensor output signals are compensated to determine if the sensor is contaminated.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a temperature sensor is placed close to the micro-electromechanical sensor for direct temperature measurement, then temperature measurement accuracy is improved, but the device complexity and risk of thermal interference increase

Engineering Contradiction:

Improvetemperature measurement accuracyVSAvoidsensor arrangement complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a heater as an intermediary element that indirectly measures temperature through the micro-electromechanical sensor's response to controlled thermal energy. Instead of placing a temperature sensor in direct contact with the MEMS sensor, the system uses the heater to deliver thermal energy and observes the sensor's temperature-dependent signal changes, eliminating the need for direct temperature sensing while maintaining measurement capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical/physical temperature sensor with an electrical signal-based detection method. Instead of using a temperature sensor that directly measures thermal conditions, the system uses the micro-electromechanical sensor's electrical output signal, which changes predictably with temperature, to infer temperature information. This substitution eliminates the need for direct thermal contact and associated complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If the micro-electromechanical sensor is heated to detect contamination through temperature changes, then contamination detection capability is improved, but energy consumption increases

Engineering Contradiction:

Improvecontamination detection capabilityVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic or pulsed heating instead of continuous heating to detect contamination. The heater is activated in controlled cycles, delivering thermal energy to the micro-electromechanical sensor and then allowing cooling periods. This periodic action enables contamination detection through temperature-dependent signal analysis while significantly reducing overall energy consumption compared to continuous heating operations.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent applies partial heating action, delivering thermal energy in controlled amounts sufficient to elicit detectable signal changes from the micro-electromechanical sensor without requiring excessive heating. The heater is controlled to provide just enough thermal energy to observe temperature-dependent effects, avoiding unnecessary energy consumption while maintaining effective contamination detection capability.

Inventive Principle:

Principle #16Partial or excessive action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method efficiently detects contamination by analyzing changes in compensated sensor output signals relative to temperature changes, allowing for accurate determination of sensor cleanliness.

Implementation Method 1

Outputting control signals for controlling the heater so that the heater generates thermal energy to heat the micro-electromechanical sensor

Methodology Applied

Scientific EffectThermal energy transfer: Conduction (thermal)

Implementation Method 2

receiving temperature sensor output signals representing temperatures measured by the temperature sensor at different times during the generation of thermal energy by the heater

Methodology Applied

Scientific EffectTemperature measurement: Temperature Gradient

Implementation Method 3

receiving sensor output signals representing physical quantities measured by the micro-electromechanical sensor at different times during the generation of thermal energy by the heater

Methodology Applied

Scientific EffectTemperature-dependent physical quantity measurement: Thermal Expansion

Data Source

PatentUS20250059025A1Method for detecting contamination of a MEMS sensor

Publication Date: 2025.02.20 ROBERT BOSCH GMBH

AI summary

A method for detecting contamination of a micro-electromechanical sensor of a sensor module using a heater, wherein the sensor module has a temperature sensor arranged at a distance from the heater and from the micro-electromechanical sensor. The heater heats the sensor, which is measured by the temperature sensor. The sensor measures physical quantities at different times. The measured physical quantities are compensated based on the temperatures measured at the different times. It is ascertained based on the compensated physical quantities and the temperature difference between the different times whether the micro-electromechanical sensor is free of contamination or has contamination. A system for detecting contamination of a micro-electromechanical sensor of a sensor module, a computer program and a machine-readable storage medium, are also described.