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Here, an unobtrusive, adhesive‐integrated electrode array for continuous monitoring of stomach electric activity is introduced. This patient‐friendly, disposable peel‐and‐stick adhesive device represents an important advancement over existing arrays that require placement of each electrode individually and are thus also labor intensive and are in general more rigid and cumbersome. In comparison to other silver–silver chloride electrodes, this skin conformal array does not require gel and thus can withstand low impedance over the duration of long recordings. Interfacing these electrodes with miniaturized electronic recording and wireless telemetry systems has the potential to enable scalable population health opportunities to perform objective gastrointestinal assessment and optimization of treatment regimens.

Additive patterning of transparent conducting metal oxides at low temperatures is a critical step in realizing low‐cost transparent electronics for display technology and photovoltaics. In this work, inkjet‐printed metal oxide transistors based on pure aqueous chemistries are presented. These inks readily convert to functional thin films at lower processing temperatures (T≤ 250 °C) relative to organic solvent‐based oxide inks, facilitating the fabrication of high‐performance transistors with both inkjet‐printed transparent electrodes of aluminum‐doped cadmium oxide (ACO) and semiconductor (InO_x). The intrinsic fluid properties of these water‐based solutions enable the printing of fine features with coffee‐ring free line profiles and smoother line edges than those formed from organic solvent‐based inks. The influence of low‐temperature annealing on the optical, electrical, and crystallographic properties of the ACO electrodes is investigated, as well as the role of aluminum doping in improving these properties. Finally, the all‐aqueous‐printed thin film transistors (TFTs) with inkjet‐patterned semiconductor (InO_x) and source/drain (ACO) layers are characterized, which show ideal low contact resistance (R_c< 160 Ω cm) and competitive transistor performance (µ_linup to 19 cm²V⁻¹s⁻¹, Subthreshold Slope (SS) ≤150 mV dec⁻¹) with only low‐temperature processing (T≤ 250 °C).

This work describes a flexible and stretchable battery pack configuration that exhibits highly stable performance under large deformation up to 100% biaxial stretching. Using stress‐enduring printable inks and serpentine interconnects, the new screen‐printing route offers an attractive solution for converting rigid battery units into a flexible, stretchable energy storage device. Coin‐cell lithium ion batteries are thus assembled onto the island regions of a screen‐printed, buckling‐enabled, polymer‐reinforced interconnect “island‐bridge” array. Most of the strain on the new energy‐storage device is thus accommodated by the stress‐enduring serpentine structures, and the array is further reinforced by mechanically strong “backbone” layers. Battery pack arrays are assembled and tested under different deformation levels, demonstrating a highly stable performance (<2.5% change) under all test conditions. A light emitting diode band powered by the battery pack is tested on‐body, showing uninterrupted illumination regardless of any degrees of deformation. Moreover, battery‐powered devices that are ultrastable under large deformation can be easily fabricated by incorporating different electronics parts such as sensors or integrated circuits on the same platform. Such ability to apply traditionally rigid, bulky lithium ion batteries onto flexible and stretchable printed surfaces holds considerable promise for diverse wearable applications.