The concept of transient electronics emerged to minimize E-waste. Ideal transient electronics operate equivalent to conventional electronics, and the entire device disintegrates after a stable operation period. The discovery of graphene opened a new realm of two-dimensional(2D) material science. 2D materials appealed to the attention of the scientific community on account of their combinations of electronic, optical, robust mechanical, and chemical properties that are characteristically distinct from their parental 3D materials. Furthermore, the diverse inclusion of different electronic/optical properties of 2D material makes them advantageous entrants towards novel electronics/ optoelectronics applications. Near atomic thick two-dimensional (2D) molybdenum disulfide (MoS2) terminated with sulfide anions poises minimal toxicity. However, 2D TMDs integrated optoelectronic transient devices and their intrinsic transient characteristics are not extensively explored. A green approach, such as water-assisted integration of 2D MoS2, only requires water and paves the way for integrating 2D MoS2 into any arbitrary substrate, i.e., biodegradable cellulose and Ca-alginate for potential transient electronics. Our studies outlined the feasibility of integrating 2D MoS2 and biodegradable and biocompatible metals/substrates in transient electronics. We drafted a water-assisted green integration of 2D MoS2 on biodegradable cellulose and curved/ tubular natural rubber substrate. We also edged the integration of calcium alginate on 2D MoS2 as an active device component. We demonstrated proof-of-concept 2D MoS2 integrated transient electronics, i.e., pressure sensor, photodetector, biodegradable electrolyte gated 2D MoS2 field effect transistor (FET). In this study, we outlined the dissolution characteristics of 2D MoS2 using food ingredient baking soda buffer solution; furthermore, we studied a novel approach of ultraviolet, UV-triggered degradation of 2D MoS2 on calcium alginate incorporated with riboflavin polymer matrix. Overall, our study sketched the likelihood of integrating 2D MoS2 towards transient electronic devices, and transient characteristics of 2D MoS2 enabled on biodegradable polymers.

Compliant electronics are an emerging class of electronics which offer physical flexibility in their structure. Such mechanical flexibility opens up opportunities for wide ranging applications. Nonetheless, compliant electronics which can be functional in unusual environments are yet to be explored. Unusual environment can constitute a harsh environment where temperature and/or pressure is much higher or lower than the usual room temperature and/or pressure. Unusual environment can be an aquatic environment, such as ocean/sea/river/pond, industrial processing related liquid and bodily fluid environment, external or internal for implantable electronics. Finally, unusual environment can also be conditions when extreme physical deformation is anomalously applied to compliant electronics in order to understand their performance and reliability under such extraordinary mechanical deformations. Therefore, in this thesis, three different aspects of compliant electronics are thoroughly studied, addressing challenges of material selection/optimization for unusual environment applications, focusing on electrical performance and mechanical flexible behavior. In the first part, performance of silicon-based high-performance complementary metal oxide semiconductor (CMOS) devices are studied under severe mechanical deformation. Next, a high-volume manufacturing compatible solution is offered to reduce the usage of toxic chemicals in semiconductor device fabrication. To accomplish this, Germanium Dioxide (GeO2) is simultaneously used as transient material and dielectric layer to realize a dissolvable/bioresorbable transient electronic system which can be potentially used for implantable electronics. Finally, wide bandgap semiconductor Gallium Nitride is studied to understand its mechanical flexibility under high temperature conditions. In summary, this research contributes to the advancement of material selection, optimization and process development towards achieving compliant and transient devices for novel applications in unusual environments.

The objective of this doctoral thesis is to develop, engineer and investigate an amorphous metal tungsten nitride (aWNx) and to study its functionality for applications focused on electromechanical system at the nano-scale. Charge transport based solid state device oriented complementary metal oxide semiconductor (CMOS) electronics have reached a level where they are scaled down to nearly their fundamental limits regarding switching speed, off state power consumption and the on state power consumption due to the fundamental limitation of sub-threshold slope (SS) remains at 60 mV/dec. NEM switch theoretically and practically offers the steepest sub-threshold slope and practically has shown zero static power consumption due to their physical isolation originated from the nature of their mechanical operation. Fundamental challenges remain with NEM switches in context of their performance and reliability: (i) necessity of lower pull-in voltage comparable to CMOS technology; (ii) operation in ambient/air; (iii) increased ON current and decreased ON resistance; (iv) scaling of devices and improved mechanical and electrical contacts; and (v) high endurance. The “perfect” NEM switch should overcome all the above-mentioned challenges. Here, we show such a NEM switch fabricated with aWNx to show (i) sub-0.3-volt operation; (ii) operation in air and vacuum; (iii) ON current as high as 0.5 mA and ON resistance lower than 5 kΩ; (iv) improved mechanical contact; and the most importantly (v) continuous switching of 8 trillion cycles for more than 10 days with the highest switching speed is 30 nanosecond without hysteresis. In addition, tungsten nitride could be the modern life vine by fulfilling the demand of biodegradable material for sustainable life regime. Transient electronics is a form of biodegradable electronics as it is physically disappearing totally or partially after performing the required function. The fabricated aWNx suites this category very well, despite not being a universal bio-element. It has been found that aWNx dissolves in ground water with a rate of ≈ 20-60 nm h-1. This means that a 100 nm thick aWNx disappears in ground water in less than a day and three days are enough to dissolve completely a 300 nm thickness device.

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