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FDC1004QEVM: Human Body Detection Capability of FDC1004QDGSRQ1

Bhavin Pankhaniya
Prodigy 10 points
Part Number: FDC1004QEVM
Other Parts Discussed in Thread: FDC1004

Tool/software:

Dear TI Support Team,

I am currently working on a device that requires non-contact human body detection, and I came across the FDC1004QDGSRQ1 capacitive sensing IC. I would like to confirm whether this sensor is capable of detecting the presence of a human body through capacitive sensing, specifically when the sensor is embedded inside a protective safety suit.

My primary goal is to determine whether the suit is being worn by a person (i.e., detect human presence inside the suit) using this sensor. Could you please confirm:

  1. Can the FDC1004QDGSRQ1 reliably detect the human body through clothing or suit material?

  2. If not suitable, could you kindly recommend a TI sensor or solution that would be better suited for non-contact human presence detection, particularly for this application?

Your prompt response would be highly appreciated, as it will help guide the next steps in our design process.

Please let me know if any further details are required

  • 0
    TI__Mastermind 40295 points

    Bhavin,

    Your proposed application sounds hopeful.

    It sounds like this is really about detecting skin.
    Human skin generally looks like a lossy ground plane to a capacitive sensor, and that leads to a couple of factors to consider:

    1. There should be no conductive material and/or objects near the sensors, or between the sensors and the body/skin to be detected.
    2. The sensors should be positioned close to the skin to allow the best chance of detection.
    3. Any cloth or other material between the sensor and skin should have well-understood electrical properties, such as permittivity  and very low conductivity.
      The permittivity will impact the sensor design (area) and the distance between the sensor and skin. 
    4. Many times, the main factors that determine success or failure of a sensor application are the mechanical requirements. 
      For example, packaging, dimensions, surrounding materials....

    More info on the FDC1004 can be found on the E2E FDC1004 Frequently Asked Questions page, including a comprehensive list of collateral, and a crash course that covers features, applications and major specs.

    I hope this helps. Please let me know if you have any questions, or if there are other considerations that need to be considered for this application.

    regards,
    John

  • 0 in reply to John Miller - Sensing
    Prodigy 10 points

    Dear TI Support Team,

    Thank you for your detailed response and the helpful guidance regarding the FDC1004QDGSRQ1.

    As a follow-up, could you please help clarify the following points for our specific use case:

    1. If the sensor is embedded inside a PCB and placed inside a safety suit, can it reliably detect the presence of a human body (through the suit material)?

    2. What is the maximum effective detection range of the FDC1004 for identifying human presence through non-contact capacitive sensing?

    Our goal is to ensure accurate detection when the suit is worn, without false triggers when the suit is empty or folded. Understanding the range and sensitivity limitations will help us finalize the mechanical design and placement.

    Looking forward to your confirmation and recommendations.

  • 0 in reply to Bhavin Pankhaniya
    TI__Mastermind 40295 points

    Bhavin,

    A capacitive sensor may not be able to distinguish between a human body and another conductive object.
    For example, if there is residual moisture inside the suit (by intrusion or perspiration) to the point where the inner fabric was wet, as opposed to the normal dry condition, the sensor may behave as though the suit is being worn by a user.

    The effective detection range and reliability will depend on the sensor electrode area, geometry, and the suit's materials surrounding the electrode. 
    Without knowing more about that, it is impossible to make judgements on reliability, false triggers, etc.

    All of that being said, I do think there is great potential to use capacitive sensing for your application.
    The key will be to define the high-level requirements in more detail.
    Even though capacitive sensors are electronic devices, it is usually necessary to know the mechanical requirements of the system before sensor design and performance can be considered.

    For example:

    1. What are the materials used in the suit and their thicknesses?
    2. How do you expect to embed the capacitive sensors/electrodes in the suit material?
    3. Will the suit's user have the option of wearing additional clothing inside the suit such as to accommodate a cold climate?
      If so, will the clothing always be known? This can help define distances between the electrodes and the wearer.
    4. You mentioned "... false triggers when the suit is empty or folded." .
      Will the capacitive sensor be powered up when the suit is put on, and powered off when the suit is removed and/or stored?

    If factors like these can be considered & discussed, then we make some progress in answering your original two questions.

    Regards,
    John