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In this paper, we consider the design challenges and solutions for achieving both good electrical performance and convenience of use for skin wearable electronics. User convenience includes both enhancing the benefit of using the device and minimizing the interference with normal life caused by the device. The electrical performance includes reliability of conductors and inter-connections to discrete components, as well as the RF performance of the antenna for wireless communication. We discuss flexibility and stretchability as solutions for user convenience, but also consider the negative effects they cause for the electrical reliability. Further, we identify size and height as important factors for both convenience and RF performance.

Industrial internet will improve process control and increase efficiency to maximize industrial output. Key enabling technologies include low-power wireless communication, energy harvesting power autonomous devices along with the latest in sensing devices. This paper presents a wireless sensing system developed for the key industrial application of condition monitoring, specifically; valve leakage detection. The system integrates advances in all of the three aforementioned topics. A novel MEMS-based acoustic emission sensor is described to detect valve leakage manifested as vibrations in certain frequency bands. An in-house developed ultra-low power wake up radio technology, which enables the deployment of this sensor, will be presented. Two energy-harvesting systems: thermal harvesting in the sensor node and an industrial current loop harvester for the base station are developed. Integration and piloting of this system is described and evaluation results presented. The system presented offers a repeatable and adaptable sensor system deployed for valve leakage detection in an ATEX industrial environment.

A key barrier to the penetration of IoT technologies is the need for an independent power source for sensor nodes, increasing complexity and cost and hindering the convenience of deployment and maintenance. To address this formidable challenge, the authors have been developing a fully passive wireless sensor network platform, the Zero Power Sensor. The sensing mechanism is by now maturing and a platform has been implemented and readout distances in excess of 10 meters have been demonstrated. A method of addressing and activating the sensor nodes using bias applied by passive UHF RFID with digital output is demonstrated on one sensor node at a distance of 2m.

Every material which dissipates electrical energy generates thermal noise power that is related to the temperature of that material. This work exploits this effect to measure the average absolute temperature within a vessel. We present a technique for the measurement of core temperature based on inductive noise telemetry; where a loop antenna is magnetically coupled to a saline solution. Dissipations in the antenna are dominated by the solution and therefore the noise measured in the antenna is dominated by the noise in the solution. This work demonstrates a noise measurement of 0.67 pV/°C/VHz, approaching the theoretical calculated noise in the solution. The noise thermometry system is demonstrated, in ideal conditions and a temperature measurement resolution of 0.2°C is achieved.