This low-cost, conductive material offers a simple and accessible alternative to traditional bioelectrical measurement tools, potentially transforming both research and educational practices.
Researchers from the University of Massachusetts Amherst have unveiled use for homemade play putty in monitoring brain, heart, muscle, and eye activity. Their study reveals the conductive potential of “squishy circuits,” a material that acts as a simple, low-cost alternative to conventional bioelectrical measurement tools. “Squishy circuits are essentially play putty that also conducts electricity,” explained Dmitry Kireev, assistant professor of biomedical engineering and lead author of the study. The putty is composed of everyday ingredients such as flour, water, salt, cream of tartar, and vegetable oil, with salt providing the conductivity.
Traditionally used as an educational toy to teach children about circuits, the research team demonstrated that the material has potential far beyond arts and crafts. The team utilized squishy circuits to measure bioelectrical signals from the human body, capturing data such as brain activity (EEG), heart activity (ECG), eye movement (EOG), and muscle contraction (EMG). The team found that the squishy circuits matched the performance of commercially available gel electrodes in terms of impedance, a key factor in measuring bioelectrical potentials. Impedance refers to the resistance between two materials, with lower impedance leading to better signal quality. The study also highlighted the affordability and versatility of the material. A single squishy circuit electrode costs about one cent, significantly cheaper than commercial electrodes, which range from $0.25 to $1.
The putty can be molded to fit the contours of the skin, reused multiple times, and easily reformed if it breaks apart. By comparison, the materials like carbon nanotubes, graphene, and silver nanowires are costly, fragile, and difficult to manufacture. The team emphasized the accessibility of squishy circuits, suggesting that anyone could create these electrodes at home or in educational settings. The study credits undergraduate students from UMass Amherst for their contributions, several of whom are continuing their research in graduate programs.Reference: More information: Squishy bioelectronic circuits, Device (2024). DOI: 10.1016/j.device.2024.100553. www.cell.com/device/fulltext/S2666-9986(24)00475-7
