Simplex Inter-IC for Wearables and Its Applications

Akihito Noda,Hiroyuki Shinoda

doi:10.1109/access.2021.3078133

Akihito Noda, Hiroyuki Shinoda

Open Access

https://doi.org/10.1109/access.2021.3078133

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Abstract

We propose a simplex version of Inter-IC for Wearables (I2We), which enables the simultaneous transfer of Inter-Integrated Circuit (I22C)-formatted serial bitstream and dc power over a single transmission line consisting of a pair of conductive textiles. In a previous study, a half-duplex I2We (HD-I2We) was proposed for power and data transfer among microcontrollers and sensors distributed on a relatively small piece of conductive textile. The passive modulation operation of HD-I2We was implemented in a small footprint by designing a special filter. However, to extend the conductive textile area to cover the human body as clothing does, the filter design requires unrealistically low-loss circuit components. Simplex I2We (S-I2We) does not require these unrealistic components. This paper also presents demonstration systems in which LEDs and actuators are attached to jackets composed of conductive textiles. The proposed S-I2We will enable the implementation of wearable and flexible sensor/actuator systems in the form of daily wear.

Highlights

F LEXIBLE electronic components and modules, including sensors and actuators that are intended to be used in wearable systems, have been extensively investigated [1]– [4]
As can be interpreted from (3), the ratio V1H/V1L decreases with a low impedance of the transmission line (TL) and/or a large number of modulators connected in parallel to the same TL
We present Simplex I2We (S-I2We) to achieve a simultaneous transfer of dc power and serial bitstream on low-ZT TLs without adding carrier oscillators to the slaves

Summary

INTRODUCTION

F LEXIBLE electronic components and modules, including sensors and actuators that are intended to be used in wearable systems, have been extensively investigated [1]– [4]. As can be interpreted from (3), the ratio V1H/V1L decreases with a low impedance of the TL and/or a large number of modulators connected in parallel to the same TL These two factors will be critical for practical wearable systems that use significantly large-area conductive textile TLs and contain many tiny communication modules. The minimum detectable amplitudes increase as CT increases; they are indicated by negative values in decibels Based on these results, we can conclude that S-I2We can operate on low-ZT TLs, as low as 1 Ω under the condition that the carrier strengths are appropriately tuned to obtain well-balanced CIRs. The effective sensitivity of the demodulator degrades; it is only a signal attenuation on the low-ZT TL caused by the internal impedance of the signal generator. This assumption would be invalid for conductive inkjet/screen prints using conductive nanoparticles

APPLICATION SYSTEMS

VIBRATOR-DISTRIBUTED TACTILE DISPLAY JACKET

CONCLUSION