Evaluating research in flexible electronics requires weighing evidence across multiple technical and manufacturing dimensions. However, current LLM-based approaches largely rely on unstructured text and generic evaluation criteria, limiting their ability to assess scientific work at the device level. We present FlexSciEval, a multi-agent framework that first turns each paper or research plan into an auditable structured record, then uses dimension-specific agents to score academic impact, fabrication realizability, and novelty. We also construct a 60-paper expert-annotated benchmark for validation and scale the framework to 4,158 papers. FlexSciEval reduces overall mean absolute error by 10.4% compared with direct LLM evaluation on the benchmark annotated by experts, although gains vary by model and dimension. These results indicate that grounding LLM evaluation in structured and dimension-specific evidence improves the reliability of automated scientific assessment in the field of flexible electronics, providing a practical basis for more reliable agent-based evaluation in experimental device research in the future.