Sherjeel M. Khan

Mechanical response of spiral interconnect arrays for highly stretchable electronics

A spiral interconnect array is a commonly used architecture for stretchable electronics, which accommodates large deformations during stretching. Here, we show the effect of different geometrical morphologies on the deformation behavior of the spiral island network. We use numerical modeling to calculate the stresses and strains in the spiral interconnects under the prescribed displacement of 1000u2009μm. Our result shows that spiral arm elongation depends on the angular position of that particular spiral in the array. We also introduce the concept of a unit-cell, which fairly replicates the deformation mechanism for full complex hexagon, diamond, and square shaped arrays. The spiral interconnects which are axially connected between displaced and fixed islands attain higher stretchability and thus experience the maximum deformations. We perform tensile testing of 3D printed replica and find that experimental observations corroborate with theoretical study.

CMOS Enabled Microfluidic Systems for Healthcare Based Applications

With the increased global population, it is more important than ever to expand accessibility to affordable personalized healthcare. In this context, a seamless integration of microfluidic technology for bioanalysis and drug delivery and complementary metal oxide semiconductor (CMOS) technology enabled data-management circuitry is critical. Therefore, here, the fundamentals, integration aspects, and applications of CMOS-enabled microfluidic systems for affordable personalized healthcare systems are presented. Critical components, like sensors, actuators, and their fabrication and packaging, are discussed and reviewed in detail. With the emergence of the Internet-of-Things and the upcoming Internet-of-Everything for a people-process-data-device connected world, now is the time to take CMOS-enabled microfluidics technology to as many people as possible. There is enormous potential for microfluidic technologies in affordable healthcare for everyone, and CMOS technology will play a major role in making that happen.

Compliant plant wearables for localized microclimate and plant growth monitoring

The microclimate surrounding a plant has major effect on its health and photosynthesis process, where certain plants struggle in suboptimal environmental conditions and unbalanced levels of humidity and temperature. The ability to remotely track and correlate the effect of local environmental conditions on the healthy growth of plants can have great impact for increasing survival rate of plants and augmenting agriculture output. This necessitates the widespread distribution of lightweight sensory devices on the surface of each plant. Using flexible and biocompatible materials coupled with a smart compact design for a low power and lightweight system, we develop widely deployed, autonomous, and compliant wearables for plants. The demonstrated wearables integrate temperature, humidity and strain sensors, and can be intimately deployed on the soft surface of any plant to remotely and continuously evaluate optimal growth settings. This is enabled through simultaneous detection of environmental conditions while quantitatively tracking the growth rate (viz. elongation). Finally, we establish a nature-inspired origami-assembled 3D-printed “PlantCopter”, used as a launching platform for our plant wearable to enable widespread microclimate monitoring in large fields.Flexible electronics: plants can now wear sensorsThe application of flexible electronics has been shifted from epidermal sensors to the surface of individual plant for microclimate and growth condition monitoring. Prof M. M. Hussain and colleagues from King Abdullah University of Science and Technology, Saudi Arabia develop wearable electronic system for plants with localized monitoring function. They borrow the wisdom from human wearable electronics to adopt and re-design the flexible, lightweight and biocompatible materials and electronic components to match the field requirements of plants-wearable electronics. They show integrated temperature, humidity and strain sensing and real-time plant growth monitoring and diagnosing. The approach reported in this work is potentially scalable to be applied to large fields and opens up the possibilities to customized investigation and optimization in plant sciences.

Compliant lightweight non-invasive standalone “Marine Skin” tagging system

Current marine research primarily depends on weighty and invasive sensory equipment and telemetric network to understand the marine environment, including the diverse fauna it contains, as a function of animal behavior and size, as well as equipment longevity. To match animal morphology and activity within the surrounding marine environment, here we show a physically flexible and stretchable skin-like and waterproof autonomous multifunctional system, integrating Bluetooth, memory chip, and high performance physical sensors. The sensory tag is mounted on a swimming crab (Portunus pelagicus) and is capable of continuous logging of depth, temperature, and salinity within the harsh ocean environment. The fully packaged, ultra-lightweight (<2.4u2009g in water), and compliant “Marine Skin” system does not have any wired connection enabling safe and weightless cutting-edge approach to monitor and assess marine life and the ecosystem’s health to support conservation and management of marine ecosystems.Marine sensory tags: a non-invasive solutionA cost-effective multi-sensory tag system has been developed by integrating wireless communication, high performance physical sensors and conformal packaging for marine research. A collaborative team led by Prof Muhammad Hussain from King Abdullah University of Science and Technology, Saudi Arabia designs a non-invasive, wireless, lightweight epidermal multisensory tag with long deployment lifetime for marine research applications. To show the non-invasive and lightweight features of the “Marine Skin” tags, they test their long term temperature, pressure, salinity and their cross-sensitivity on the crustaceans in Red Sea water for more than 20 days. The sensory tags can be tailored for a diversity of animals of irregular size and shape due to the non-invasiveness and conformality of the functional circuits and packaging materials. They enable cost-effective solutions for long term monitoring and measuring.

In-plane and out-of-plane structural response of spiral interconnects for highly stretchable electronics

Stretchable electronics are commonly used as a diverse class of interconnected architectures, which accommodate large strain during stretching. A systematic understanding of the underlying mechanism of these interconnects, i.e., stress/strain states is essential to optimize the spiral designs. Here, we demonstrate the in-depth structural response of the spiral-island system when subjected to in-plane and out-of-plane stretchings. We use numerical modeling to simulate the stresses and strains along the arm of the spiral when stretched at a prescribed displacement of 1000u2009μm. We show the strain contours for spirals connected in-series. Our results show that the additional spirals connected in-series share the prescribed displacement equally and thus lower the von Mises stresses and principal strains. We also compare the stress generated in arms for single spiral and triangular configurations, especially when we stretch out these configurations in-plane and out-of-plane. The evolved stress depends on the ang...

Democratized electronics to enable smart living for all

With the increased global population, smart living is an increasingly important criteria to ensure equal opportunities for all. Therefore, what is Smart Living? The first time when we tossed this terminology seven years back, we thought reducing complexities in human life. Today we believe it more. However, smart living for all complicates the technological need further. As by all, we mean any age group, any academic background and any financial condition. Although electronics are powerful today and have enabled our digital world, many as of today have not experienced that progress. Going forward while we realize more and more electronics in our daily life, the most important question would be how. Here we show, a heterogeneous integration approach to integrate low-cost high performance interactive electronic system which are physically compliant. We are redesigning electronics to redefine its purposes to reconfigure life for all to enable smart living.