The use of machine learning in computational molecular design has great potential to accelerate the discovery of innovative materials. However, its practical benefits still remain unproven in real-world applications, particularly in polymer science. We demonstrate the successful discovery of new polymers with high thermal conductivity, inspired by machine-learning-assisted polymer chemistry. This discovery was made by the interplay between machine intelligence trained on a substantially limited amount of polymeric properties data, expertise from laboratory synthesis and advanced technologies for thermophysical property measurements. Using a molecular design algorithm trained to recognize quantitative structure—property relationships with respect to thermal conductivity and other targeted polymeric properties, we identified thousands of promising hypothetical polymers. From these candidates, three were selected for monomer synthesis and polymerization because of their synthetic accessibility and their potential for ease of processing in further applications. The synthesized polymers reached thermal conductivities of 0.18–0.41 W/mK, which are comparable to those of state-of-the-art polymers in non-composite thermo-plastics.

Machine learning is emerging as a powerful tool for the discovery of novel high-performance functional materials. However, experimental datasets in the polymer-science field are typically limited and they are expensive to build. Their size (< 100 samples) limits the development of chemical intuition from experimentalists, as it constrains the use of machine-learning algorithms for extracting relevant information. We tackle this issue to predict and optimize adhesive materials by combining laboratory experimental design, an active learning pipeline and Bayesian optimization. We start from an initial dataset of 32 adhesive samples that were prepared from various molecular-weight bisphenol A-based epoxy resins and polyetheramine curing agents, mixing ratios and curing temperatures, and our data-driven method allows us to propose an optimal preparation of an adhesive material with a very high adhesive joint strength measured at 35.8 ± 1.1 MPa after three active learning cycles (five proposed preparations per cycle). A Gradient boosting machine learning model was used for the successive prediction of the adhesive joint strength in the active learning pipeline, and the model achieved a respectable accuracy with a coefficient of determination, root mean square error and mean absolute error of 0.85, 4.0 MPa and 3.0 MPa, respectively. This study demonstrates the important impact of active learning to accelerate the design and development of tailored highly functional materials from very small datasets. Graphical abstract

Mesoporous PtPdAu alloy films with the highest electrocatalytic activity are discovered by the active learning approach using Bayesian optimization.

In materials science, the amount of observational data is often limited by operating protocols that require a high level of expertise, often machine-dependent, developed for a time-consuming integration of valuable data. Scanning electron microscopy (SEM) is one of those methodologies of characterisation for which the number of observations of a given material is limited to just a few images. In the present study, we present the possibility to artificially inflate the size of SEM image datasets from a limited ( $$\mathrm \sim 100s-1000s$$∼ 100 s - 1000 s of images) to a virtually unbounded number thanks to a generative adversarial network (GAN). For this purpose, we use one of the latest developments in GAN architectures and training methodologies, the StyleGAN2 with adaptive discriminator augmentation (ADA), to generate a diversity of high-quality SEM images of $$\mathrm 512\times 512$$512 × 512 pixels. Overall, coarse and fine microstructural details are successfully reproduced when training a StyleGAN2 with ADA from scratch on at most 3000 SEM images, and interpolations between microstructures are performed without significant modifications to the training protocol when applied to natural images.