This talk will discuss a few nanofabrication approaches targeting various applications, and would like to use photonic structures and optoelectronic devices as a motivator. Light interacting with metallic and dielectric structures can produce various interesting optical effects, e.g. structural colors can be produced by exploiting optical resonances in various resonator structures, offering advantages over conventional colored pigments such as high brightness, durability, and environmental safety and sustainability. To enable many scientific findings for real world applications, means to practically fabricate the structures often presents a bottleneck. We show that scalable nanopatterning techniques can facilitate large area manufacturing. Roll-to-roll process can scale to industrial level, e.g. to realize transparent conductors based on ultra-thin Ag film with many applications such as in flexible displays and touch screens. We also exploit a nozzle-free photoacoustic printing process to directly print highly viscous material or even solid molecules. Simpler structures often lead to more practical fabrications. As an example, structure colors can be designed and made by additive physical vapor deposition processes, or even with solution processes. Modern deep learning can significantly speed up the search for the optimal structures and provide researchers the opportunity to choose among multiple designs that is easiest to realize.

A defining feature of living organisms lies in their efficient use of surfaces to dynamically interface with environments for a continuous flux and exchange of water, energy, heat, and information. The ubiquity and diversity of these elegant natural surfaces construct the Surface of Things (SOT), reminiscence of In the Internet of Things (IOT) which has received vast attention and widely penetrated into our daily life. Despite extensive progress, particularly triggered by learning from nature, the power and magic of natural surfaces evade our deep scrutiny, and it also appears challenging to design, manufacture and adopt artificial SOTs that exhibit high performances as their natural counterparts. The challenges originate from the complexity in adopting one surface design to resolve many seemingly contradictory properties to yield optimized functions for many practical applications, especially in harsh environments.

In this talk, I will reveal intriguing property-function relationships on natural surfaces and then design, manufacture nature-inspired SOT with tailored complementary properties in topography, wetting, thermal/electrical conductivity, stiffness to overcome the inherent tradeoff otherwise associated with homogeneous design for water, energy, environment and healthcare applications.

Micro-, nano-, and molecular technology enable solving major problems of societal relevance. I will present the following examples:

One of the main pillars of modern diagnostics is the precise quantification of disease markers using biosensors. Non-specific binding (NSB) is the archenemy of such diagnostic biosensors.¹ With the example of focal molography², I will show how diffraction based read-out along with coherent referencing enables real-time, label-free measurements of molecular binding in complex samples, such as plasma³ or live cells⁴.

Stochastic sensing deals with NSB by statistical means. Nanopore-based biosensors not only provide the possibility of detecting single molecules, but the characteristic peaks in translocation events also enable their identification. Here, I will introduce a force-controlled nanopore sensor with scanning capabilities that allows analysing the content of live cells and the characterization of cell-cell communication.⁵

The traditional way of addressing questions related to the function of the brain involves studying the nervous system of various organism. However, this at the same time means to study something that is highly complex and largely unknown. My third example will show how special micro-⁶ and nano-⁷ structures can be used to build and study well-defined, small neural networks towards fundamental neuroscience⁸ and personalized medicine⁹.

The field of organic electronics such as organic light-emitting diodes, organic photovoltaics, and organic field effect transistors has been developed vastly in the last three decades because they are mechanically flexible, light weight, versatile in chemical design and synthesis, and can be easily processed as well. In such organic devices, microstructures of organic semiconductor thin films and interfacial properties of the devices are key factors to determine the device performance and lifetime. Especially, controlling the surface characteristics of underlying substrates can govern the mesoscale and/or nanoscale ordering of the organic molecules assembled on them, and thus significantly affects the devices on the whole. In this talk, I will discuss basic principles on the surface-directed molecular assembly and introduce several approaches to grow the high-quality organic semiconductor thin films for the organic electronic/energy device applications.

Simple microorganisms can move in complex media, respond to the environment and self-organize. The field of nano- and microrobotics takes inspiration from nature and strives to achieve these functions in mobile robotic systems of sub-millimeter size. However, building synthetic motors, machines, and robots ‘bottom up’, such that they can mimick biological matter and function autonomously or such that they can be controlled externally, is a fascinating challenge that requires a multidisciplinary approach. It is generally not possible, to directly translate actuation mechanisms and design-concepts from the macro- to the nanoscale. At this scale, different physical phenomena are important and there are no ready-made motors and no off-the-shelf parts. One key requirement is the need for nano- and microfabrication methods that can be used to build 3D functional structures and a means to actuate the structures. Any biomedical applications of the robotic systems also typically require large numbers and hence fast, parallel fabrication methods. In this talk, I will describe the use of parallel nanofabrication methods to achieve functional magnetic structures, as well as the possibility to use acoustic fields for the instant fabrication of complex soft microstructures. Challenges in fluidics, in the actuation with magnetic and acoustic fields, and in their application in the field of gene delivery and tissue penetration will be addressed. I will also discuss ways to achieve the exciting prospect of building living machines.

Micro-Electro-Mechanical Systems (MEMS) play a critical role in various fields, from consumer electronics to healthcare and environmental monitoring. However, the need for external power sources to operate these devices can limit their functionality and make them less reliable and sustainable. To address these challenges, self-powered MEMS has emerged as a promising solution. In self-powered MEMS, the device generates its own electrical energy to power its components. This eliminates the need for external power sources and enhances the reliability and sustainability of MEMS devices. There are several pathways to achieve self-powering in MEMS via the integration of mechanical energy harvesters (triboelectric/piezoelectric), photovoltaics, thermoelectric, and hybrid devices with flexible energy storage (planner and micro SCs) systems in both intrinsic and extrinsic configuration. Each approach has its own advantages and disadvantages, and the best approach will depend on the specific requirements of the MEMS device and its operating environment. Finally, we provide an overview of the growing problems, tactics, and possibilities for the development of new and innovative self-powered wearable electronics, MEMS, and IOT devices.