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Strain sensors with wide range stretchability, good sensitivity, high gauge factor, and reliability are needed for several applications. Herein we present stretchable strain sensors capable of operating over multi-strain range and having excellent gauge factor. The systematic study, carried out with different combinations of elastomer, conductive filler and graphene-carbon paste (GCP), revealed that the sensors exhibit excellent stretchability when only filler particles are present in the elastomer, and they exhibit high sensitivity when filler particles are mixed with GCP. The molecular dynamics simulations show that the addition of GCP to the elastomer- filler composite helps to attain the excellent sensor response with wide range stretchability. Thus, sensors response can be tuned by using selected material composition. Accordingly, the strain sensor with 50 wt.% GCP revealed 500% stretchability and a maximum gauge factor of 504. Likewise, 150 wt.% GCP loading led to sensors with 45% stretchability and an unprecedented gauge factor of 1834140. The capability to detect the small- to large-scale strains make the presented sensors attractive for monitoring the movements by body parts – which range from small movements during facial expression to large movement experienced by the limb joints.

“Heterogeneous Integration” is a promising approach for high-performance hybrid flexible electronics that combine printed electronics and silicon technology. Despite significant progresses made by integrating rigid silicon chips on flexible substrates, the integration of flexible ultra-thin chips (UTCs) on flexible foils remains a challenge as they are too fragile for conventional bonding methods. Reliable interconnects (low-resistivity and mechanical robustness) and bonding of UTCs are critical to the realization of hybrid flexible systems. Herein, using a non-contact printing approach, an easy and cost-effective method for accessing UTCs on flexible foils is demonstrated. The high-viscosity conductive paste, extruded from a high-resolution printer (1–10 µm line width), is used here to connect the metal oxide semiconductor field effect transistors (MOSFETs) on UTCs with the extended pads on flexible printed circuit boards (PCBs). The electrical characterization of MOSFETs, before and after printing the interconnects, reveals an acceptable level of variation in device mobility (change from 780 to 630 cm2 V−1s−1). This is due to the drop in effective drain bias voltage as a marginally small electrical resistance (≈30 Ω) is added by the printed interconnects. The bonded UTCs show robust device performance under bending conditions, indicating high reliability of both the chip thinning and bonding methods.

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) is presented. After studying in detail the influence of ZnO NWs dispersion medium and metal-ZnO NWs contacts, a novel fabrication approach employing the structural engineering on NWs-elastomer composite is used to achieve high stretchability. The fabricated ZnO NWs-based UV PDs, embedded inside kirigami-inspired honeycomb-patterned elastomeric substrate, exhibit unprecedented stretchability (up to 125%) and high-performance with photo/dark current ratio of ≈5 × 105, responsivity of ≈54 A W−1, and a fast recovery time of 100 ms. Further, the stretchable PD is coupled with flexible TENGs to demonstrate a self-powered system for potential application in real-time UV radiation monitoring using advanced wearable healthcare technology.

Inorganic material‐based devices are well known for their high performance, excellent stability, and hence suitability for fast computation and communication. But their nonflexibility and nonstretchability often hinder their application in several emerging areas where conformability with irregular 3D surfaces is required in addition to the high performance. Herein, with honeycomb like patterns, the omnidirectional stretchability and conformability of inorganic material‐based device are demonstrated without sacrificing the performance. The simple method presented here facilitates the transfer of patterned inorganic material‐based devices from rigid poly(methyl methacrylate) (PMMA)/glass substrate onto flexible/stretchable substrate such as polydimethylsiloxane simply by placing a water droplet at the PMMA/glass interface. As a proof of concept, the intrinsically brittle indium–gallium–zinc oxide (IGZO)‐based stretchable photodetector devices are fabricated. These devices can be stretched up to 10% without performance degradation, which is a significant improvement considering the less than ≈1% fracture limit of IGZO. With Au decoration, these devices show 127‐fold higher responsivity (295.3 mA W−1) than planar IGZO devices. The higher fracture strain together with the omnidirectional stretchability underpinned by the honeycomb pattern could allow presented devices to conform to complex hemispherical surfaces such as the human eyes, thus showing significant potential for future high‐performance stretchable electronics.