1- Proposal Title: Stretchable Planar Antenna Modulated by Integrated Circuit (SPAMIC) for the Near Field Communication (NFC) of Epidermal Electrophysiological Sensors (EEPS)
2- Brief description of project Goals:
To investigate and implement stretchable planar antenna modulated by integrated circuit for the near field communication of epidermal electrophysiological sensors.
3- Abstract:
a) Nontechnical Abstract: Epidermal electrophysiological sensor (EEPS) is a class of skin mounted, non-invasive, ultra-thin electrophysiological (EP) sensors with softness matching human epidermis. They are considered the most intimate and comfortable wearable sensors for long term EP monitoring including electrocardiogram (ECG), electromyogram (EMG), and electroencephalogram (EEG). EEPS has a great potential to transform both mobile health (mHealth) and human-machine interface (HMI) if the low power and wireless operation of EEPS can be realized. Out of many wireless technologies, near field communication (NFC) is chosen because it can wirelessly transmit both power and data, which makes it possible to bypass both batteries and bulky wireless modules on the EEPS. Therefore the proposed wireless EEPS will house only three components: stretchable gold EP electrodes, aluminum stretchable planar antenna (SPA), and one single millimeter-sized integrated circuit (IC) chip. Stretchable EP electrodes and SPA have been successfully manufactured, hence the research objective can be achieved through the following three research tasks: i) the rational design, characterization, and optimization of skin-mounted SPA, ii) the design of the ultra-low-power, zero-external-component IC for EEPS data acquisition (DAQ) and NFC, and iii) the integration of the three components and the validation of the wireless EEPS. The proposed SPAMIC technology will enable the first low cost, battery-free, wireless EEPS with minimum rigid component. The impact on mobile health and HMI can be disruptive because it will make possible more affordable, dependable, long term, and unobstructive EP monitoring in comparison with existing expensive and confining systems. The education and outreach objective of this proposal is to tightly integrate the research efforts and results with graduate, undergraduate, and K-12 education and to globally disseminate both research and the education outcomes.
b) Technical Abstract: Although the unprecedented thinness and compliance of EEPS offer ultimate conformability to human skin and long term wearability, microprocessors, wireless communication modules, and batteries cannot be manufactured as thin and soft as the EEPS very easily. Cables that connect the EEPS to the DAQ are not only obstructive, but also a major source of motion artifacts and interference. We propose to develop stretchable planar antenna modulated by integrated circuit (SPAMIC)-enabled battery free, wireless EEPS with three unprecedented merits: artifact-minimized EP measurement, long term wearability, and low cost. Despite the many merits of NFC, there are two major challenges to implement NFC for EEPS: i) Although the SPA can be made as thin as stretchable as EEPS, its operation can be significantly affected by bio-integration and mechanical deformation. Therefore the first intellectual merit of the proposed work is the fundamental understanding of the electrical/mechanical/bio coupling of skin-mounted SPA and the holistic design paradigm of SPA enabled by this fundamental understanding. ii) The power harvested from NFC is very limited especially at long distance and in the presence of large frequency detuning due to bio-coupling. Thus, the second intellectual merit is the design of ultra-low-power IC and applying on-chip frequency compensation to mitigate the dynamic variation of bio-integrated SPA. The transformative aspect of this work arises from the broad applicability of SPAMIC to other wearable and even implantable devices when they try to go wireless.
