# Transfer, integration, and inverse design of metasurfaces in suspended membranes

## TL;DR

This paper introduces a new method for creating flexible metasurfaces that can be transferred and integrated onto various surfaces, enabling advanced optical applications.

## Contribution

The paper presents the OPTIMISM method for universal and scalable metasurface transfer and integration using suspended membranes.

## Key findings

- OPTIMISM enables metasurface transfer to non-conventional substrates and devices.
- Inverse design strategies outperform conventional methods in ultrathin metasurface design.
- The surrounding refractive index significantly affects metasurface performance.

## Abstract

Despite the vast promise of abrupt wavefront engineering within subwavelength thickness, most optical metasurfaces are still bound to bulky and rigid substrates. Recently, metasurfaces in suspended membranes (MISMs) have attracted increasing attention due to their unique flexible, conformal properties and their ability to minimize undesired substrate effects. Most importantly, the MISM platform enables metasurface transfer and integration with non-conventional substrates and electronic/photonic devices. By summarizing multiple approaches to create MISMs with a variety of membrane and sacrificial layer materials and configurations, we demonstrate the Omni-Purpose Transfer and Integration of Metasurfaces in Suspended Membranes (OPTIMISM), overcoming the existing limitations on metasurface geometries or materials. It is particularly suitable for metasurface integration on optical fiber tips to form meta-optic probes for broad applications, including biomedical and endoscopic imaging and sensing. Considering the various configurations of membrane dielectric environment in integrated MISM devices, we performed a systematic investigation to demonstrate the strong influence of the surrounding refractive index on ultrathin metasurface design based on both conventional forward design (library search) and inverse design strategy (evolutionary algorithm). Our findings highlight the advantage of the inverse design strategy leveraging meta-atom non-local interactions, and the great potential of the MISM platform for universal and scalable metasurface transfer and integration.

The online version contains supplementary material available at 10.1007/s44275-026-00041-y.