Inter-IC for Wearables (I²We): Power and Data Transfer Over Double-Sided Conductive Textile

Abstract

We propose a power and data transfer network on a conductive fabric material based on an existing serial communication protocol, Inter-Integrated Circuit (I 2 C). We call the proposed network Inter-IC for Wearables (I 2 We). Continuous dc power and I 2 C-formatted data are simultaneously transferred to tiny sensor nodes distributed on a double-sided conductive textile. The textile has two conductive sides isolated from each other and is used as a single planar transmission line. I 2 C data are transferred along with dc power supply based on frequency division multiplexing (FDM). Two carriers are modulated with the clock (SCL) and the data (SDA) signals of I 2 C. A modulation and demodulation circuit is designed to enable using off-the-shelf I 2 C-interfaced sensor ICs. One significant originality of this work is that a special filter to enable passive modulation is designed by locating its impedance poles and zeros at appropriate frequencies.The proposed scheme enables flexible implementation of wearable sensor systems in which multiple off-the-shelf tiny sensors are distributed all over a wear.

A Multifunctional Integrated Circuit Router for Body Area Network Wearable Systems

“…A power and data transfer network on conductive fabric material, which is based on the I 2 C protocol is proposed in [26]. In this system, I 2 C data are transferred to tiny sensor nodes distributed on a double-sided conductive textile along with DC power supply using a scheme based on frequency division multiplexing.…”

“…The systems presented in [13], [31], [33], [36] include only a few sensors. In contrast, those proposed in [17], [21], [26] are capable of supporting more sensors but in practice they may not exceed several tens of sensors due to the increased load on the communication line which reduces the communication speed and increases the power consumption as well. The circuit presented in this article can support up to hundreds of sensors without slowing down the communication speed.…”

Broadband Low-Loss On-Body UHF to Millimeter-Wave Surface Wave Links Using Flexible Textile Single Wire Transmission Lines

“…First of all, avoiding the need for cumbersome interconnections required to transfer data using on-body interconnects [13]. To explain, transferring digital information with datarates exceeding a few kilobits per second requires complex e-textile buses [14], which increases the amount of conductive material required to realize a wired network of wearable devices compared to a wireless solution [3]. Therefore, a range of on-body antennas have been developed to maximize the channel gain between wearable devices [15]- [17].…”

Fast half-duplex communication on e-textile based wearable networks

“…1. Two conductive layers are isolated from each other, working as a single planar bus for both power and data transfer shared by all devices mounted on the textile [3]. This kind of two-dimensional communication (2DC) textile has the following benefits: it is robust to textile wrinkling and partial breakage of conductive mesh; the number and position of distributed devices on the textiles are customizable; also, it partly retains the flexibility of the original base textile not to hinder the user's body movement.…”

“…A simultaneous power/data transfer approach by applying frequencydivision-multiplexing (FDM) was verified by Noda et al, and about 100 kbps twowire serial communication on the textile has been proved. However, the data rate is limited depends on carriers used for modulation/demodulation [3]. To increasing data rate, Noda et al presented a baseband transmission system without modulation/demodulation carriers based on another serial transmission protocol: universal asynchronous receiver/transmitter (UART).…”