Kirigami and Mogul‐Patterned Ultra‐Stretchable High‐Performance ZnO Nanowires‐Based Photodetector

Abstract

lenging. [5] Therefore, highly stretchable photodetector (PD) devices having the potential to attach on nonplanar surfaces such as clothes or skin to endure body motions are highly desirable for real-time monitoring of UV radiation under diverse environmental conditions. [6] Additionally, for real-time operation the self-powering of myriad sensors and electronics on wearable systems is desirable. [7] Enormous efforts have been made to achieve stretchable UV PDs to go beyond the existing silicon-based rigid electronics. [8] These solution typically adopt the techniques that have developed for stretchable and wearable electronics, which has gained significant interest in recent years because of the need for electronics in flexible form factors in a wide range of applications. [9] Few examples include mobile health monitoring through sensory skin patches, [10] communication through wearable devices or foldable displays, [8c,11] safe robotic interaction through large area tactile skin, etc. [12] On-going research efforts focus on the development of multimodal wearables that can be easily integrated in clothing, wrist watches and bands, tattoo-like sensory skin patches (electronicskin), etc. [13] To this end, highly sensitive sensors with high stretchability and reliability are recommended for accurate and fast measurements during body movements. [14] The stretchable PDs are fabricated thus far either use novel structural device engineering [8b,14a,15] or the nanowires (NWs)elastomer nanocomposite by embedding the semiconducting NWs in the elastomeric material. [8c,8d,8f,16] The former approach relies on the structural design of nonstretchable materials which includes the fabrication of PD through a conventional approach and transfer to the prestretched substrate to obtain a stretchable wavy pattern upon releasing the prestrain. For example, a stretchable graphene PD was fabricated by transferring graphene layer to a prestretched polydimethylsiloxane (PDMS) membrane to achieve wavy graphene with enhanced stretchability. [17] Similarly, patterning the nonstretchable active materials such as InGaZnO and gold to stretchable geometries such as serpentine, zigzag, or honeycomb [18] has been explored. Alternatively, stress-absorbing substrates, namely, mogul [15] or kirigami [8b] patterned substrates have been utilized to achieve stretchable PDs. [8b,15] However, most of the PDs have limitations either in the device performance, [8b,c,17] such as poor photocurrent ratio and slow response/recovery time or in the device Wearable UV photodetectors (PDs) have attracted interest recently for detection of excess exposure of the skin to the UV radiation. Despite numerous advances made in this direction, many challenges remain, particularly in terms of device reliability under extreme mechanical deformations simultaneously and self-powering, etc. Herein, a self-powered stretchable PD developed with kirigami-inspired honeycomb-patterned zinc oxide (ZnO) nanowires (NWs) and coupled with a triboelectric nanogenerator (TENG...

In Tandem Contact‐Transfer Printing for High‐Performance Transient Electronics

“…Further, the figure shows that photocurrent increases from ≈0.5 μA (dark current) to ≈5 μA (2 μW cm −2 ) in 365 nm UV light (one order change in photocurrent) at V D = 1 V. The working mechanism for ZnO NW based PDs is well documented. [ 32 ] Briefly, in the dark condition, the absorbed oxygen molecules on the NW surface results in the depletion of electrons. The electron depletion leads to upward band bending and an electric barrier across the MS interface.…”

Recent Advances in Self-Powered Piezoelectric and Triboelectric Sensors: From Material and Structure Design to Frontier Applications of Artificial Intelligence

“…Recently, a novel charge-excitation TENG based on a Miura folding structure was developed by integrating flexible PET (as a folding substrate with a double working side design: Furthermore, the kirigami structure is also used for TENGs in electronic skin. Dukhyun et al [126] reported an ultrathin and stretchable acrylic acid ([PEO/PAA]n) ethylene oxide and double-layer positive triboelectric film, which was manufactured using a low-cost and environmentally friendly layer-by-layer method. The composite film was used to design a shape-adaptive kirigami nanogenerator.…”

Finite element analysis of stress distribution in soft sensors under torsional loading

“…Reliable and robust soft sensors in flexible and stretchable form factors are of significant interest in application such as robotics [1][2][3], the internet of things [4][5][6], healthcare [7][8][9], electronic skin (e-skin) [10][11][12][13][14][15][16], etc. These sensors are critical in these applications for accurate feedback based on reliable measurements of various stimuli of interest such as pressure, strain etc.…”

“…Therefore, greater attention is needed to predict the response of flexible systems under various mechanical deformations [19][20][21]. Whilst few attempts have been made in this regard, most of the previous studies have focused only on the analysis of mechanical stress distribution and its effect on device performance under tensile and compressive bending and stretching conditions [13,19,[22][23][24][25][26]. Whilst these encouraging works mark a step in the right direction, a very few of them have aimed to understand the stress evolution under twisting (torsional) loading [17,18,27].…”