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Abstract Natural systems, synthetic materials, and devices almost always feature interphases that control the flow of mass and energy or stabilize interfaces between incompatible materials. With technologies transitioning to non‐planar and 3D mesoscale architectures, novel deposition methods for realizing ultrathin coatings and interphases are required. Polymer networks are of particular interest for their tunable chemical and physical properties combined with their structural integrity. Here, the electrodeposition of polymer networks (EPoN) is introduced as a general approach to uniformly coat non‐planar conductive materials. Conceptually, EPoN utilizes electrochemically activated crosslinkers as polymer end groups to confine their network formation exclusively to the material surface upon charge transfer, yielding a passivating and self‐limiting growth of conformal and uniform coatings with tunable submicron thickness on conductive materials. EPoN is found to result in thin functional films of various polymer backbones and side group chemistries as demonstrated for poly(ether) and poly(acrylamide) based polymers as solid electrolyte and thermally responsive interphases, respectively. 

Abstract Foams are versatile by nature and ubiquitous in a wide range of applications, including padding, insulation, and acoustic dampening. Previous work established that foams 3D printed via Viscous Thread Printing (VTP) can in principle combine the flexibility of 3D printing with the mechanical properties of conventional foams. However, the generality of prior work is limited due to the lack of predictable process‐property relationships. In this work, a self‐driving lab is utilized that combines automated experimentation with machine learning to identify a processing subspace in which dimensionally consistent materials are produced using VTP with spatially programmable mechanical properties. In carrying out this process, an underlying self‐stabilizing characteristic of VTP layer thickness is discovered as an important feature for its extension to new materials and systems. Several complex exemplars are constructed to illustrate the newly enabled capabilities of foams produced via VTP, including 1D gradient rectangular slabs, 2D localized stiffness zones on an insole orthotic and living hinges, and programmed 3D deformation via a cable‐driven humanoid hand. Predictive mapping models are developed and validated for both thermoplastic polyurethane (TPU) and polylactic acid (PLA) filaments, suggesting the ability to train a model for any material suitable for material extrusion (ME) 3D printing.