Rational Assembly of Liquid Metal/Elastomer Lattice Conductors for High‐Performance and Strain‐Invariant Stretchable Electronics

Abstract

Highly stretchable and conductive composites have gained tremendous research interests due to the imperative demands in the fields of stretchable electronics and soft robotics. However, it is challenging to maintain the original performance of the composites under complex external deformations. Here, a one‐step dual‐material 3D printing technique is developed to rationally assemble liquid metal (LM) into an elastomer lattice. The 3D interconnected and deformable liquid conductive network is supported by a highly ordered and robust polydimethylsiloxane lattice skeleton, yielding the resultant composites high electrical conductivity (1.98 × 106 S m−1), stretchability (180%), and electromagnetic interference (EMI) shielding effectiveness (72 dB). Unlike those composites with dispersed fillers, the LM/elastomer lattice composites deliver negligible electromechanical coupling, showing a negative resistance change of only −2% at a large tensile strain of 100%. The composites also exhibit strain‐invariant EMI shielding performance in a strain range of 0–100%, and present exceptional stability over 1000 rigorous cycles of stretching and releasing. The applications of the composites in flexible display circuits, microwave shielding layer, and EMI shields in wireless power transmission systems are demonstrated. The current findings suggest an effective strategy for fabricating LM‐based composites with precisely controlled and unprecedented multi‐functionality.

Stretchable conductors for stretchable field-effect transistors and functional circuits

“…23(d)), which rationally assembles LM into a robust lattice skeleton of polydimethylsiloxane, exhibiting the resultant composite's high electrical conductivity and stretchability of 1.98 Â 106 S m À1 and 180%, respectivety. 433 For more convenient printing, through associating structural-design theory with 3D printing technique, additive-free free-standing stretchable electrodes have been exploited on the basis of a PEDOT:PSS ink (poly(3,4-ethylenedioxythiophene):polystyrene sulfonate) (Fig. 23(e)).…”

Designable Electrical/Thermal Coordinated Dual‐Regulation Based on Liquid Metal Shape Memory Polymer Foam for Smart Switch

“…[31,32] Based on the desirable properties of LM, the large-range deformable LM elastomer composites (LMECs) have been obtained by adding LM into stretchable and flexible substrates, [12,33,34] which can ensure the continuity of LM fillers in a relative high deformation range. To obtain LMECs, researchers have tried different methods, such as directly mixing LM particles into elastomer matrix (Ecoflex 00-30, [34][35][36] PDMS [37] or other elastomer [38] ), or injecting LM to elastomer foams prepared by template or foaming method. [39,40] Those LMECs have exhibited excellent electrical [40,41] or thermal adjusting, [34,42] but there are only a few works that can realize the electrical and thermal conductivity simultaneously so far.…”

Multifunctional Wearable Silver Nanowire Decorated Leather Nanocomposites for Joule Heating, Electromagnetic Interference Shielding and Piezoresistive Sensing

“…However, the brittleness, large density, complex fabrication processes and high cost of ITO greatly limit its application areas. [12,13] Conductive polymer composite (CPC) materials composed of conductive nanomaterials and flexible polymer substrates such as polydimethylsiloxane (PDMS), [14][15][16] polyurethane (PU), [17][18][19] polystyrene-butadiene-styrene (SBS) [20] and aramid nanofibers (ANFs) [21][22][23][24] have been investigated extensively owing to their high flexibility and versatile potential applications, and have gained significant progress. [25][26][27][28] For instance, Bao and co-workers demonstrated that the stretchable nanostructured PDMS films can be endowed with desirable multi-functions including piezoresistive sensing with unprecedented sensitivity, [29] light-emitting display [30] and semiconducting [31] for ultra-flexible skin electronics.…”