第42回「センサ・マイクロマシンと応用システム」シンポジウム（以下，センサシンポジウム）は，2025年11月10日（月）～12日（水）に「ライトキューブ宇都宮」にて開催され，テクニカルツアーは11月13日（木）に実施された。本センサシンポジウムでは，基調講演1件，オーラル発

We have been studying a wearable sensor network composed of an original event-driven sensing system and multiple sensors for human motion detection. To detect human behaviors in detail, multi-point detection with high time resolution and suppression of data congestion is required. For achieving such a sensing system, this paper proposes a PID-type (Proportional-Integral-Derivative) data volume control function that variably increases and decreases data volume of each sensor node in response to large motions, continuous motions, and sudden motions of human. Basic verification using a loading stage and application verification using a wearable sensor glove showed that the sum of proportional, integral, and derivative values of sensor data changes in response to large motion, continuous motion, and sudden motion, and that the date volume changes during sensing. The effectiveness of the PID-type data volume control function was demonstrated.

This paper addresses the short battery lifespan of wireless mouse rings by introducing picoRing mouse. We develop a near-field sensitive inductive telemetry, which allows a ring coil to send its data to nearby wristband coil in ultra-low-power way. This approach drastically extends the ring’s operation time from a few hours to over 200 hours on a 27 mAh battery.

In this study, a compact infrared sensor for non-dispersive infrared (NDIR) gas sensing is developed by integrating a thermopile with a metal-polymer layered wavelength-selective infrared absorber. The absorber consists of a metal hole array (MHA), which acts as a plasmonic wavelength selector, and an infrared-absorbing polymer layer. The absorber structure is designed using finite element method simulations and fabricated on a thermopile wafer through a low-temperature process operated below 200°C. Fourier transform infrared spectroscopy (FTIR) confirms that the fabricated absorber exhibits a clear absorption peak near 4.3 µm, corresponding to the CO₂ absorption band. Gas sensing experiments demonstrate stable detection of CO₂ concentrations ranging from 2% to 20% vol., and the sensor response follows the Lambert-Beer law over a wide concentration range. These results indicate that the proposed integration approach is effective for compact NDIR sensors with multi-band wavelength-selective characteristics.