Flexible electronics comprise magnetic sensors and organic circuits

Researchers from Dresden, Chemnitz and Osaka have developed an active matrix magnetic sensor system, according to a recent article published in Science Advances. The sensor system comprises a 2 x 4 array of magnetic sensors, an organic bootstrap shift register required for controlling the sensor matrix, and organic signal amplifiers. All electronic components are based on organic thin-film transistors and are integrated within a single platform.

Recent advancements in flexible sensors and organic electronics have provided important prerequisites for artificial skin used in robotics applications. These devices can operate on soft and elastic surfaces, whereas sensors perceive various physical properties and transmit them via readout circuits.

To closely replicate natural skin, it is necessary to interconnect a large number of individual sensors. First demonstrations were based on an array of individual sensors addressed separately, which resulted in a high number of electronic connections. In order to reduce the necessary wiring, important technology had to be developed—namely, complex electronic circuits, current sources and switches had to be combined with individual magnetic sensors to achieve fully integrated devices.

The sensor system developed by Dresden, Chemnitz and Osaka demonstrated the system's high magnetic sensitivity, and it can acquire the two-dimensional magnetic field distribution in real time. The sensor system also resists mechanical deformation, such as bending, creasing or kinking. In addition to full system integration, the use of organic bootstrap shift registers is a very important development step toward active-matrix electronic skin for robotic and wearable applications.

Prof. Dr. Oliver G. Schmidt, director at the Leibniz Institute for Solid State and Materials Research Dresden, said in the article, "Our first integrated magnetic functionalities prove that thin-film flexible magnetic sensors can be integrated within complex organic circuits. The ultra-compliant and flexible nature of these devices is an indispensable feature for modern and future applications such as soft robotics, implants and prosthetics. The next step is to increase the number of sensors per surface area as well as to expand the electronic skin to fit larger surfaces."