An origami-inspired ultrastretchable bioprobe film device

Multifunctional Two-Dimensional PtSe2-Layer Kirigami Conductors with 2000% Stretchability and Metallic-to-Semiconducting Tunability

“…Conventionally employed electronic materials with pristine forms (e.g., thin-film metals or semiconductors) exhibit a significant increase in electrical resistance with accumulating strain owing to their structural irreversibility. A variety of approaches have been explored to convert intrinsically brittle electronic materials to stress-resilient forms by rationally engineering their physical configurations and dimensions. − Among them, forming the materials into “kirigami” patterns inspired by the ancient paper-cutting art , offers distinguishable advantages for efficiently relieving external stress. − This kirigami patterning employs rows of designed cuts to a planar material, which improves its mechanical stretchability by converting applied tensile stress to torsional stress at specific points between the cuts. − In addition to structural “engineering” approaches, substantive efforts have been used to identify a new form of electronic materials which intrinsically possess suitable crystallinity to enable superior mechanical tolerance. In this endeavor, recently explored two-dimensional (2D) transition-metal dichalcogenides (TMDs) present highly unique and promising aspects. , For instance, they exhibit significantly larger in-plane strain limits over covalently bonded three-dimensional crystals owing to their van der Waals molecular bonding, offering opportunities for futuristic stretchable electronics. , Despite the projected advantages, combining these two different compelling approaches (i.e., converting 2D TMDs into kirigami forms) has been rarely attempted, leaving their anticipated mechanoelectrical superiority largely unexplored.…”

Development of a polymer based fully flexible electrode tip for neuronal micro-stimulation applications

“…In a first approach, straight-lined micro-channels were studied, and fairly large dimensions were chosen to determine a stable fabrication process (Sect. 2.2) an overall behavior of the micro-channels, which then were reduced to aim for the resolution of already existing or in development stimulation devices, 4,[9][10][11] as shown in Table I. The choice of the liquid metal alloy was made considering the future in-vivo conditions of the device.…”

“…Enhancing our own insertion process is necessary to reduce at least by half and fully match the resolution achievable on systems produced with common metal deposition processes. 4,[9][10][11]…”

“…[7][8][9] The targeted tissues and application define the resolution and resulting designs of such systems. Typically, needs of optimal positioning and adaptability of the system to the tissues lead to the use of flexible devices for external 10) and in-tissues 11) stimulation and recording. In the case of in-tissues stimulation, the integrity of the tissues 12,13) during the electrode-tissues contact period, and the minimizing of damages upon insertion of the electrodes are additional criteria in the design optimization.…”

“…High flexibility in electronics systems was reported in the literature by using thin film systems, 10,15) conductive polymers such as Ag-powder or carbon-black doped poly(dimethylsiloxane) (PDMS), 16) and liquid metal alloys liquid which are at room temperature, such as mercury or Galinstan. 17) Where thin films systems are indicated for deposition on external surface of the tissues, 10,15) the possible encapsulation of liquid alloy or conductive polymers within a functionalized polymer volume allows its use into insertable systems. 8,11,14) This volume can easily be patterned to a high degree using mask and mold replicating techniques, allowing the development of numerous designs for specific applications.…”