## 1 Introduction  
Wearable devices used in smart healthcare applications can measure the electrophysiological signals from human skin to diagnose internal conditions and diseases [1, 2, 3, 4, 5, 6]. Since the stable, long-term monitoring of biological signals is necessary to realize an accurate diagnosis, the electrical characteristics of sensors in wearable devices should not be lost, even if significantly deformed. Stretchable electrodes, for example, are not only used in wearable devices but are also epidermal and implantable sensors inserted into the body and actuators in soft robots; hence, they have gained increasing attention [7, 8]. However, if the electrodes are detached from the skin owing to their mechanical modulus mismatch, the sensed signal cannot be read correctly because of an air gap caused by an inflow of air between the skin and electrodes. Therefore, many researchers have reported stretchable electrodes that can be attached conformally to the skin and accurately measure biological signals while having stable electrical characteristics for long-term use [9, 10, 11, 12]. Conventional sensors manufactured on silicon substrates are rigid, brittle, and stiff, so it is difficult to attach them to the human body. Moreover, it is also difficult to obtain a stable signal during movements, because these sensors are not stretchable. Additionally, to achieve stable bio-signals despite these rigid properties, various methods such as buckled structure [13], noncoplanar [14], rigid islands [15], wavy interconnects, and complex geometry engineering [16; 17; 18] have been proposed. However, there is a problem with integration, because complex wavy interconnects occupy a larger area than the main sensor part. In addition, the fabrication of stretchable devices involves complicated multistep processes. Therefore, researchers have proposed intrinsically stretchable materials for stretchable semiconductors [19; 20; 21; 22; 23] and organic electrodes [9; 10; 24; 25; 26; 27; 28; 29]. Organic electrodes are soft, flexible, and soluble. Using these properties of polymers, they are made by mixing conductive fillers, such as metal nanowires and carbon materials with a flexible insulating polymer solution [24; 25; 26; 27; 28; 29], or by polymerizing intrinsically conductive polymers from a monomer unit [30; 31; 32]. However, although these organic stretchable electrodes have excellent elasticity, they do not exhibit good electrical properties. In addition, they are vulnerable to various organic solvents used in semiconductor processes, which makes their integration difficult. Therefore, it is necessary to develop an intrinsically stretchable electrode that exhibits high electrical properties by using a relatively simple fabrication process. For this demand, thermal evaporation has steadily studied for the preparation of stretchable conductors consisting of a gold nanomembrane on an elastomer surface (especially PDMS) [33; 34; 35]. It has been reported that thermally evaporated gold nanomembranes have three morphologies by the evaporation condition: microcracked, buckled, and smooth. Among them, a microcracked gold nanomembrane-based elastomer conductor has advantages in its low electrical resistance, compatibility with the conventional semiconductor fabrication process, uniformity, simple one-step process and low fatigue for an extreme cyclic test, and so on [34]. Therefore, it was recently studied as a soft bioelectronics and neural interface [36; 37; 38]. However, there is no study using styrene-ethylene-butylene-styrene (SEBS) with a gold nanomembrane. Here, we described a soft bio-integrated multifunctional device (SBMD) based on an intrinsically stretchable conducting nanomembrane supported on an elastomeric substrate. We fabricated a stretchable electrode by the direct deposition of a metal nanomembrane on the surface of a stretchable elastomer substrate using a thermal evaporator. The proposed electrodes showed that they are possible for fabricating patterned electrodes on one substrate with a simple one-step process.