Data-Driven Inverse Design of Silver Nanoparticle Size for Controlled Synthesis Across Multiple Systems Using Conditional Generative Models

This study aims to develop and systematically evaluate a data-driven inverse-design framework for determining silver nanoparticle (AgNP) synthesis conditions that achieve a prescribed particle size. To this end, a forward surrogate model is first developed to learn the nonlinear mapping from synthesis parameters to particle size, and it is then coupled with target-conditioned inverse models, including conditional generative adversarial network (cGAN), conditional Wasserstein GAN (cWGAN), conditional Wasserstein GAN with gradient penalty (cWGAN-GP), Wasserstein GAN with gradient penalty (WGAN-GP), and other comparable frameworks, to generate feasible synthesis conditions. Three AgNP datasets covering microfluidic and chemical synthesis routes are used for evaluation, and the models are assessed using both experimentally observed target sizes and constructed targets spanning the attainable output range. The results show that conditional adversarial models generally outperform the non-adversarial baselines. Among them, cWGAN shows the most consistent performance across the three datasets, while cGAN remains competitive in the more difficult inverse-design cases. The proposed framework also captures the one-to-many nature of inverse design by producing multiple candidate synthesis conditions for a single target size. In addition, prediction errors increase near the lower and upper boundaries of the feasible size interval. Inverse design is therefore more challenging near these boundaries, although the main comparative conclusions remain unchanged under stricter validation. These findings support the use of forward-constrained conditional generative modeling for target-oriented AgNP synthesis design in limited-data settings.