Research

LCE-actuated bistable optical switches

The goal of this project is to engineer and demonstrate a bistable optical system which uses light-actuation to enable autonomous optical switching. Key to the realization of such a system is the implementation of liquid-crystal elastomer-based films which can be controllably actuated in response to light stimulation combined with 3D-structured glass opto-mechanical microsystems.

• Researcher: Sruthy Dinesh
• Funding: DFG Cluster of Excellence livMatS

Dynamic liquid optics

Electrowetting has enabled the realization of tunable liquid lenses, prisms, and scanners, and recent work has demonstrated liquid interfaces with controlled optical aberrations. Building on the unique capabilities of multi-electrode tube lenses developed in previous work, which provided programmable and non-radially symmetric profiles by means of driving individually addressable electrodes, DynaLO introduces dynamic control of the liquid–liquid interface using surface waves.

Time-varying voltages applied to azimuthally distributed electrodes modulate the local contact angle around the tube lens, generating interfacial waves whose superposition can be exploited to create standing, rotational, or complex freeform patterns. This novel dynamic surface-shaping approach extends electrowetting optics beyond quasi-static operation and allows continuous modulation of complex wavefronts.

• Researchers: Aybüke Çalikoğlu & Faezeh Aghaei
• Funding: DFG

Micromachined glass optics

The MiGO project intends to develop the necessary technologies to enable 3D micro-machining of glass for fabrication of optical-quality freeform surfaces and, based on this, demonstration of complete monolithic glass micro-optical microsystems. In a first phase, laser-based origination processes for structured glass combined with thermal post-process polishing of the optical surfaces will be developed and used to fabricate a range of individual freeform optical surfaces.

The second phase will apply this technology to the realization of monolithic glass optical systems, combining mechanical with optical functionality, to demonstrate that complex ultra-miniaturized optical structures can be fabricated in a single glass substrate. As a demonstrator, an all-glass laser-diode multi-fiber coupler, based on air-suspended lightguides, with tapers and couplers, will be developed, showing that fully three-dimensional optical systems can be manufactured using the technologies developed.

• Researcher: Fahime Ghashghaei
• Funding: Lab for Micro-optics

Multimodal endoscopic system for tumor classification

The goal of this project is the development of a highly integrated medical endoscope with additional photonic sensors that supports users in characterizing neoplasms in the colon. The PhotonIQ system utilizes the sensor area of the camera sensor chip that is not used by conventional imaging to integrate additional sensors in oder to provide information for the classification of polyps in terms of color, blood flow, size, shape, surface structure, and infiltration depth.

The project is part of the consortium Entwicklung eines neuartigen photonischen Systems zur optischen Charakterisierung in der minimal-invasiven Medizin, in which five industrial, clinical and university partners collaborate on the development and clinical demonstration of this potentially disruptive new technology. We are responsible for the development and miniaturization of the sensor optics that complement the classic white light objective. This includes, among other things, the development of structured illumination that can map the topography of the polyp via pattern distortion.

• Researcher: Marie Odenthal
• Funding: BMBF

Volumetrically-programmable four-dimensional actuators

Liquid crystal elastomers (LCEs) represent an interesting class of materials, as they can undergo significant dimensional changes when properly stimulated, in directions that can be programmed during fabrication, and are thus suitable for the realization of artificial structures with programmable mechanical response.

We have developed a technology which allows a pixel-by-pixel definition of the actuation direction of these films. This unique structuring capability gives us unparalleled flexibility in defining the two-dimensional actuation behavior of an LCE film.

In this project we extend this concept into three dimensions, enabling the realization of bulk actuators which can modulate between multiple pre-determined shapes, with complete flexibility in defining the actuation direction in the bulk of the “crystal”. With high-resolution definition of the mechanical response of the bulk, we expect to be able to realize wide-ranging adaptive mechanical behavior in materials, all of which can be defined in the material design.

• Researcher: Shalini Soman
• Funding: DFG Cluster of Excellence livMatS