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Understanding the thermo‐electrical properties of different materials demands an in‐depth analysis of their structure‐property relationship. Therefore, monitoring their dynamic mechanisms in a real‐world environment is crucial to better determine how to manipulate and optimize them for various applications. For example, the capability to perform current‐voltage measurements while analyzing the corresponding structural changes during resistive switching process of the potential ReRAM materials in real time is crucial for improving the stability and scalability of the most promising next‐generation non‐volatile memory devices. Here, we present the development of a system for in‐situ biasing and heating manipulations inside the Transmission Electron Microscope (TEM), referred to as the Lightning System. The latter uses the latest Micro Electro Mechanical Systems (MEMS) based technology to scale down the experiment. Consequently, the stability and resolution can be considerably improved. The MEMS devices, known as the Nano‐Chips, act as a functional and consumable sample carrier that supplies local stimuli to the sample size required for biasing and/or heating, allowing the users to manipulate and characterize their samples. Figure 1 shows the architecture of the Nano‐Chips for simultaneous heating and biasing. As observed, it consists of eight electrical contacts, where half are used for heating and half are used for biasing purposes. As a result, the 4‐point probe measurements are used to gain complete control of each parameter and ensure instant, controllable and reproducible responses. This results in high accuracy during the measurements. The unique design of the Nano‐Chips ensures reduced specimen drift during heating, as well as a stable and chemically inert environment that enables compatibility with various types of samples (i.e. lamellas, nanowires and 2D materials). Furthermore, it empowers the user to do different types of analysis including I‐V measurements as a function of temperature (up to 800 °C) and high electric field studies. The Nano‐Chip is mounted on a functionalized holder, shown in Figure 2, which contains the contact needles to supply the stimuli from the outside world. Such holder can supply up to 100V to the Nano‐Chip for the electrical measurements and helps detecting currents in the pA regime. Furthermore, it enables tilting in alpha and beta. The complete “plug and play” system, shown in Figure 3, includes a source measurement unit and a heating control unit. Once the holder is connected to such biasing power supply and the heating controller, the voltage/current can be set and the temperature profile can be programmed for total control during the in‐situ experiment. The Lightning System can be used to understand the microstructural origins for electric field induced changes in the ferroelectric materials. As a matter of fact, it is also known that the temperature rise of ferroelectric devices during utilization limits its practical application. Therefore, the system can also enable repeating the electric field measurements while working at an elevated temperature environment. Additionally, the Lightning System can be used to study low dimensional materials like nanowires, as their electrical properties and their temperature dependence differs with different growth directions. In‐situ heating and biasing experiments of such samples can open a new application opportunity in nanoelectronics.

A nanoreactor-based system for in situ analysis of solid-gas interactions inside the transmission electron microscope, referred to as the 'climate system', is introduced here. The latter uses an micro-electro mechanical systems (MEMS)-based device as a multi-functional sample carrier and microsized laboratory for simultaneous heating and gas experiments. To assemble the nanoreactor, two chips are sandwiched together to form a minimised chemical reaction chamber. The bottom chip contains a four-point-probe microheater, which controls and introduces the heating environment (up to 1300°C) around the sample. Similarly, it contains the spacers that define the height of the gas chamber. The top chip confines the gas in the microchamber while isolating it from the external environment. Both chips contain electron transparent windows that allow the electron beam to pass through for in situ imaging. The sample can be deposited or prepared directly on the windows, which are made of silicon nitride and can sustain pressures up to 1.5 bar and high temperatures while ensuring low background atomic resolution imaging.

Nanotechnology is driving scientists to better comprehend the real‐time dynamics and structure‐property relationship of various materials and biological samples under liquid conditions. Such understanding is crucial for a wide range of applications involving, for example, nanoparticle synthesis, self‐assembly processes, (bio) molecular interactions, and biological activity in cells. In‐situ transmission electron microscopy (TEM) observations in the liquid‐phase is expected to lead to better scientific understanding, the discovery of phenomena at the nanoscale in liquid not visible before, and results in novel and innovative applications. Here we present the development of the “Ocean System”, which is an easy‐to‐use add‐on that enables in‐situ liquid studies inside the TEM (Figure 1). It consists of an optimized TEM holder that uses a microfluidic chamber as sample carrier, replacing the traditional copper grid. Such device, referred to as Nano‐Cell, acts as a multi‐functional and micro‐sized laboratory that keeps the sample in a fully hydrated state. Furthermore, the system includes an external test station that guarantees the safe loading of the holder into the TEM. Each Nano‐Cell consists of two chips (Figure 2) that are sandwiched together to form a sealed microfluidic compartment. Both chips are covered with silicon nitride providing an electron transparent window and ensuring their chemical inertness and biocompatibility. Samples are prepared directly onto the electron transparent windows, which allow for the electron beam to pass through for in‐situ imaging. Biological cells can also be directly grown on the chips. In order to control the liquid thickness to improve imaging resolution, the experiment can be customized by selecting the best‐suited spacer based on sample size. Having direct access to the electron transparent windows enables local functionalization of the membrane's surface, empowering the user to further control the microfluidic environment. The holder tip contains a precision slot with various alignment poles that ensure self‐alignment of the top and bottom chips. Similarly, it contains a by‐pass structure that prevents overpressures during liquid handling, and that allows rapid liquid exchange in the tubing, since the flow cross‐section in this channel is much larger than that of the liquid path between the chips. The tip closure mechanism uses alignment balls, so that the tip correctly closes when screws are tightened independently on the applied force. The mechanism prevents over‐compression of the O‐rings and ensures that no shear stress will be transferred to the Nano‐Cell, as these could damage fragile samples (i.e. biological cell). Additionally, the modular design ensures reliable results with easy replacement of all holder parts, such as tubing, holder tip and the Nano‐Cell (Figure 3). This is particularly important, as it prevents cross‐contamination between different experiments, and the tubing can be easily replaced by the user if these become clogged. In addition, the tip can be rotated by 180°, so that depending if one wants to use TEM or STEM, the optimal resolution can be achieved for the sample, i.e. TEM achieves the highest resolution for objects below a liquid layer for a downward traveling electron beam, while the opposite is true for STEM. The Ocean System can be used to study dynamic processes of nanoparticles. E.g. gold nanoparticles can be loosely attached to a SiN membrane. Their detachment during the experiment can be triggered by increasing the induced electron dose. This can provide useful information such as the interaction of nanoobjects (e.g. agglomeration, self‐assembly, sintering) in different liquids. Figure 4 shows Au nanoparticles being attached to the SiN membrane. Upon imaging at higher magnifications the nanoparticles start moving along the SiN membrane and start to form agglomerates. Particle tracking was applied to 4 selected Au nanoparticles to study their movement.