Cthulhu Safety Information

We have done our best to make this product safe and easy to use. However, certain hazards exist that users should review before use or before deciding to use.

Electric Shock

Placing the electrode array of the Cthulhu Shield or any electronics in your mouth comes with the inherent risk of electric shock. When designing the Cthulhu Shield, we took steps to reduce the risk of electric shocks occurring. These measures included limiting the capacitance on the device to a safe level as defined by Underwriters Laboratories, labeling the device to warn users about plugging their device into unsafe power supplies, and providing a grounding cable for users to properly ground their device before use. Plugging the device into an non-UL approved computer or power adapter, or any damaged equipment, not using the grounding cable, damaging the board, or contacting PCB components with metallic objects increases the risk of electric shock. Additionally other hazards may exist that can increase the risk of electric shock. Use the Cthulhu Shield at your own risk.

Choking Hazard

Placing foreign objects in your mouth can cause choking. Use the provided electrode array at your own risk.


The technology used in the Cthulhu Shield has been tested by hundreds of participants over decades of research with no adverse effects reported. However, users should discontinue use if they experience any irritation.

Occasionally, some people report a tingling sensation that persists for a period of time after use, this is due to the nerves in the tongue continuing to be hypersensitive after prolonged stimulation with the Cthulhu and is not harmful or dangerous and will eventually subside.

The electrode array on the device contains copper which can cause an allergic reaction in some individuals. If you experience tongue or oral mucosa irritation while using the device, discontinue use immediately. The copper used in the electrode array is contained in plastic, and exposed pads are coated in chemically inert gold. This gold coating can degrade with prolonged use (hundreds of hours) and the arrays should be discarded at this point.

The arrays are manufactured using materials and techniques which are standard for many medical devices and have been used to manufacture medical electrode arrays for decades. They comply with RoHS, Sony SS-00259 standards and should not contain any materials in concentrations which are hazardous to human health. However, users are advised to discontinue use and alert Sapien LLC if they experience any irritation when using the devices.

Information about the materials used in the electrode array is provided below:

Cthulhu Polyimide-Copper Substrate Electrode Array.

The mouthpieces supplied with the Cthulhu are manufactured in China and are composed of polyimide, copper, adhesive, and gold plating. There are trace amounts of toxic chemicals found in the adhesive used to cover the copper traces inside the electrode arrays. This adhesive is encapsulated in polyimide and is not in contact with your body at any time.

Electrode arrays and medical devices using these materials have been used for decades with no adverse effects, and the oral tissues do not directly contact this adhesive during use. The amounts of these chemicals present in the electrode arrays are extremely small.

While we do not believe that there are any health risks due to the presence of these chemicals, we are provided the following information regarding the composition of the material used in the electrode array to the end so that they may make their own informed decision about using these arrays.

If you experience any irritation or adverse effects while using this product discontinue use immediately and contact Sapien LLC.

Datasheets on the materials used in this array can be found at the bottom of this page. 

Dupont Pyralux KP

Dupont Polyimide laminated copper clad films have been used in oral electrode arrays, and implants in direct contact with human tissues with no adverse effects. We do not believe that there is a significant health risk associated with use of this material in the electrode array.

Halogen free Coverlay (manufactured by ITEQ) is composed of the following materials.

PI film 11.65~19.19% by wieght

Polyimide film used in medical products in direct contact with tissue. We do not believe that there is a significant health risk associated with use of this material in the electrode array.

          Release Paper 58-75%

                                Not used in final product

Adhesive 13-23%

BPA 43%

Nitrile butadiene rubber 30.59%

      • Is used in many products (including rubber gloves) and we do not believe that there is a significant health risk associated with the presence of this chemical in the electrode array. More information can be found here.

ATH 17%

DDS 2.54%– resin hardener

      • Hardener, antibiotic, used to treat acne, eczema, leprosy, poisonous in large doses (dapsone, diaminodiphenyl sulfone)
      • Antibiotic dose, 50mg per day, up to 300mg per day
      • Estimated 6mg of DDS inside the portion of the electrode array that is in contact with the mouth. One would consume approximately one tenth of one daily dose of DDS (for acne treatment) if one was to bite off and swallow a piece of the array. Chemical is inside cured adhesive, between two layers of PI, and not in direct contact with any oral tissues.
      • Due to the small concentration found in the adhesive of the mouthpiece (which is not in direct contact with any oral tissues) we do not believe that there is a significant health risk associated with the presence of this chemical in the electrode array.
      • More information can be found below

Dicyanodiamide (DICY) 0.52%


Phosphinate (Hypophosphorous acid) 6%