Forehead e-Tattoo for Mental Workload Estimation

Forehead e-Tattoo. © Device/Huh et al. 2025

Forehead e-tattoo is a wireless sensor that sticks like a temporary tattoo, recording brain and eye signals (EEG and EOG).

Monitoring a person’s mental state in real time can improve the safety and performance of systems that rely on human input.

Traditional EEG and EOG devices are often too bulky, with wires and long setup times, making them hard or impossible to use during real-world tasks.

Forehead e-Tattoo. © Device/Huh et al. 2025

The e-tattoo uses special adhesive electrodes made from a PEDOT: PSS composite and graphite-coated polyurethane (APC-GPU), combined with a flexible, battery-powered circuit for collecting and sending data wirelessly.

We used this device to measure brain and eye signals during a memory task and found that the results reflect changes in mental workload. This shows the e-tattoo can be used to estimate mental effort in real-world settings.