LEGO-like assembly of peelable, deformable components for integrated devices

Abstract

The development of various technologies has led to the advent of a variety of deformable devices. Despite significant technological advancement in this area, it is still challenging to integrate different devices due to limitations such as substrate issues and differences among growth and deposition conditions. Creating an interconnection between two different devices currently requires the use of metallic wires/lines to build electrical connections. Here, we demonstrate a LEGO-like assembly of the free-standing film of individually operable components encapsulated in a polymer overcoat layer, leading to the production of an integrated architecture without additional electrical connections. The free-standing components are produced by the peeling-off process. The sticky nature of the polymer layer enables the construction of supercapacitor arrays and simple RLC circuits by interlocking the individual components. We expect that this approach will enable the fabrication of a variety of custom-built devices using a LEGO-like assembly method. We demonstrate a LEGO-like assembly of free-standing film of individually operable components encapsulated in a polymer overcoat layer, leading to the integrated architecture without additional electrical connection. The free-standing components are produced by the peeling-off process. The sticky nature of polymer layer enables the construction of supercapacitor arrays and simple RLC circuits through interlocking the individual components. In a collaboration between South Korea and the United States, John Rogers, Ungyu Paik and co-workers have developed a simple process to fabricate flexible circuits by assembling the separate components in the manner of Lego blocks. The researchers first prepared each part — for example a resistor, inductor or capacitor — by depositing metal layers on a common substrate comprising a silicon dioxide wafer. Next, they grew carbon nanotubes at locations determined to be electrodes and subsequently added a gel electrolyte layer. On drying, this gel converts to a sticky polymer that incorporates the required component and can be peeled away from the substrate. The resulting film is flexible and resistant to repeated bending, folding and stretching. Lastly, these free-standing components were simply interlocked into an integrated circuit without the need for further electrical connections. Poly(vinyl alcohol), the polymer used in the study, can also be functionalized, enabling the creation of more complex devices.