Wearable sensors are susceptible to degradation from physical wear, moisture, and desiccation, which can result in signal attenuation and unreliable data. This pilot study, conducted in a controlled single-participant setting, introduces a framework to quantify and characterize sensor degradation while restoring corrupted electromyography (EMG) signals. Four types of sensors—polyethylene terephthalate film, parylene film, 3M bioelectrode pads, and microneedle patches—were affixed to the left forearm in a three-electrode EMG configuration. Impedance at 100 Hz was monitored as an indicator of sensor aging, while a one-dimensional convolutional autoencoder was employed to reconstruct degraded EMG signals using a loss function that incorporated both time-domain and frequency-domain error terms. The reconstruction loss showed a correlation with impedance changes, providing a practical metric for assessing sensor health. These findings highlight the feasibility of real-time signal recovery and its potential to extend the lifespan of sensors.
Conventional machining technologies such as a milling process have limitations in accuracy to fabricate microstructures. Deep X-ray lithography using the synchrotron radiation is a promising micromachining process with an excellent accuracy, whereas there are difficulties in the fabrication of multi-layered structures. Therefore, it is mainly used for fabricating simple monolayered microstructures with a high aspect ratio. In this study, a novel technology for fabricating multi-layered microstructures is proposed by combining two processes. In advance, an X-ray resist material is cut and machined into various shapes and heights by the micro milling process. Subsequent X-ray irradiation process facilitates the fabrication of multi-layered microstructures. The proposed technology can overcome the limitation of the pattern accuracy in conventional milling process and the difficulty of the multi-layered machining in x-ray process. The usefulness of the proposed technology is demonstrated in this study by applying the technique in the realization of various multi-layered microstructures.
We present a droplet-manipulation method using opto-thermal flows in oils. The flows are originated from Marangoni and buoyancy effects due to temperature gradient, generated by the adsorption of light on an amorphous silicon thin film. Using this method, we can transport, merge and mix droplets in an extremely simple system. Since the temperature rise during the operation is small, this method can be used for biological applications without the damage on cell viability.