IMEK > Research and Projects > Elektrische Messysteme > SMART Sensor Particles

SMART Sensor Particles

SFB1615 - Projekt A07

Since October 2023, the DFG Collaborative Research Center (Sonderforschungsbereich) SFB 1615 SMART Reactors has been established at TUHH, in which IMEK is actively involved in subprojects A02 and A07. Leveraging their expertise in impedance measurement technology and general circuit development, existing reactor controls are set to be expanded and automated.

We are facing the societal challenge of transitioning economic and production chains from fossil resources to sustainable and renewable ones. However, these resources can vary in availability and quality seasonally and geologically. Society urgently needs processes and reactors that can adapt flexibly to fluctuating resource properties. To enable such adaptation, a very high level of process control is required: pressures, temperatures, concentrations, and dispersed phases must be continuously and in situ monitored in the reactors using suitable sensors. As part of the collaborative research center, we aim to address this issue and enable SMART Reactors through fundamental research. In the future, SMART Reactors will convert sustainable renewable resources into various products (multi-purpose) in a more sustainable manner and operate autonomously (self-adjusting), resulting in more resilient processes that are better transferable between scales and locations. To achieve our vision, interdisciplinary collaboration between process engineering, materials science, and electrical engineering, along with physicists, chemists, mathematicians, and data scientists from the Technical University of Hamburg and five research institutions, allows the pooling of expertise and access to unique experimental facilities. Through this website, we aim to provide you with insights into individual subprojects, publications related to the CRC, upcoming events, and career opportunities within the collaborative research center.
TUHH SFB1615

Fluidized Bed Reactors

The A07 project focuses on measurements inside fluidized bed reactors during spray granulation.

Fluidized bed reactors are frequently used in industry and research for coating granulates. In this process, the particles are suspended and evenly mixed by an airflow. A sprayed coating material thereby distributes homogeneously on the surface of the particles. This process enables the production of products with defined properties, for example in pharmaceuticals, food technology, or materials engineering.

A central challenge lies in precisely monitoring process conditions such as flow, temperature, and humidity, as they critically influence the quality of the coating. Modern sensor systems open up new possibilities to capture the processes inside the reactor in real time, thereby ensuring a uniform, reproducible, and energy-efficient coating.

Smart Particles

In project A07, novel Lagrange sensor particles are being developed to enable the measurement of temperature, humidity, and applied coating thickness during fluidized bed spray granulation based on impedance spectroscopy. The initial prototype is not expected to exceed a size of 25 mm, with further miniaturization down to 5 mm being achieved through the design and manufacturing of an application-specific integrated circuit (ASIC). The particle's position is measured using a magnetic particle tracking setup, which is adapted for the first time to a fluidized bed spray granulation process.

SMART Particle Shell

The protective casing is designed in a spherical shape to optimally adapt in size and form to the particles of the sodium benzoate particle bed. In this way, the sensor can be fluidized together with the particles without distorting the flow conditions. The actual sensor inside is not spherical but is embedded by the casing in such a way that it behaves like a real particle in the process.

The casing is manufactured using resin printing in the stereolithography process (SLA 3D printing). This process ensures high dimensional accuracy and smooth surfaces, which enable a uniform coating in the fluidized bed process. The interior of the casing is lined with Styrodur to provide additional stability and to securely fix and protect the electronic components.

PCB Design

The sensor's electronics are developed as a compact printed circuit board (PCB) and are based on an STM32 microcontroller. This microcontroller handles wireless communication as well as the control of the measurement procedures. The signal excitation is generated by a separate signal generator IC, while the signal processing is carried out analogously to enable precise and broadband detection of the impedance spectrum.

A central challenge is miniaturization: the circuit relies on components in the 0402 format, which places high demands on design and manufacturing. Additionally, energy consumption must be consistently optimized to ensure reliable and long-term stable use in the fluidized bed process.

Micro-assembly system

The assembly unit is designed as a remote presence application, where a user can control the production of particles approximately 5 mm in size via a robotic platform. Haptic transparency is intended to convey as direct and realistic a sense of interaction with the material as possible.

Central development tasks include the control and regulation of the system. These ensure that the user's movements are precisely transmitted to the robotic platform and that feedback is provided in real time. This creates intuitive operability, enabling both precise particle production and efficient work.