When interacting with others, it’s perfectly natural to change the way we communicate based on our emotional state. You might change your tone of voice, or consider the other person’s current mood to determine if you should say certain things. From facial expressions to unusual behavior, there are many clues to how others are feeling. But even though computers are a big part of our lives and we interact with them so often, we can’t make sense of these normal emotional cues. This is a factor that prevents many applications from reaching their full potential in areas such as virtual reality, mental health devices, and even games.
Proxy measurements are commonly used because ordinary signals, which humans have no trouble interpreting, are difficult for computers to understand. In particular, electrodermal activity has proven useful in measuring levels of psychological stress. However, gathering this data is not entirely trivial. The palm is the best and most accurate place to collect this data due to the high density of eccrine sweat glands that fill under conditions of psychological stress. No! Solutions that capture the electrodermal activity of the palm are either large and obtrusive or small and fragile. Devices in the former group interfere with normal daily activities and lead to social stigma, while those in the latter group are unreliable outside of carefully controlled conditions in a laboratory.
A serpentine ribbon that deforms without breaking (📷: H. Jang et al.)
Given how palm-based sensors interfere with the wearer’s normal activities, efforts have been made to acquire signals from other parts of the body, such as wrists, shoulders, and back. Unfortunately, this has proven to be inaccurate. Signals are frequently contaminated by secretions from apocrine sweat glands that regulate body temperature.Thanks to a study by researchers at the University of Texas at Austin and Texas A&M University, we may have a better way forward. is.they have developed a process to produce Ultra-thin graphene electronic tattoo It can be applied to the palm of your hand and is almost invisible. The unique design is sufficient for the frequent bending and twisting that accompanies the area.
The team previously developed graphene electronic tattoos that are incredibly thin and well suited for measuring electrical potentials from the body, but are too fragile to withstand the strain placed on the palm. The innovation was to do away with straight wires and instead build serpentine ribbons with two overlapping layers of graphene and gold. This layout provides a high degree of strain relief and allows the conductive traces to withstand the harsh environment of the human palm.
Using the researchers’ method, electronic tattoos can be formed into sensors and wires, and their signals transferred to proximal hardware components for processing and analysis. In this case, the electronic palm tattoo was connected to a commercial smartwatch worn on the wrist. From there, the smartwatch itself can run applications that utilize this data, or wirelessly transfer it to virtual reality headsets, smartphones, or just about any other device that needs it. Given that tattoos are discreet, flexible, and durable, it’s easy to imagine a future where this technology is used in all sorts of wearable electronic devices.
