Printed human machine interfaces using touchless interaction via magnetic fields

Printed and flexible electronics have gained significant attention in recent years for their potential in various applications including medical, wearable, and Internet of Things (IoT) devices [1]. In this work, we focus on the development and characterization of printed magnetic field sensors for use in human-machine interfaces enabling the control and monitoring of various systems and devices. We developed a set of printable magnetically sensitive pastes based on microflakes and microparticles showing anisotropic [2,3], giant [4], and large magnetoresistance [5] effects. Our sensors are fabricated using cost-effective, scalable, and large-area automatized printing techniques, making them prospectively suitable for large-scale
production.
The design and production of the printed sensors are based on the properties of the paste fillers, binder, substrate, and techniques used in the fabrication process. By adjusting the mechanical properties of the binder, we were able to give the printed sensors the capability to conform to various shapes and surfaces. The use of polymeric binders in the printing process on flexible foils allowed us to laminate the sensors onto objects with complex geometries, including human skin. For example, we were able to create stretchable magnetic field sensors that can undergo 100% strain by using a styrene-butadiene-styrene block copolymer as a binder. We have also demonstrated that these sensors remain functional even when folded to a
radius of 16 µm. [4]
We have also shown that it is possible to produce large quantities of magnetic field sensors using automatized dispenser printing and laser sintering Bi pastes [5]. This method allows large-area, cost-effective, and customizable fabrication of flexible, fully printed magnetic field sensors using minimal materials. This manufacturing capability has the potential to pave the way for more extensive interactive smart surfaces and touchless control boards. Our research represents a significant advancement in the integration of printed and flexible electronics into human machine interfaces, and it opens the door for further research for creating customized solutions to user-specific needs.
[1] Y. Khan, et al. Adv. Mater. 32, 1905279 (2020)
[2] E.S. Oliveros Mata, et al. Appl. Phys. A 127, 280 (2021)
[3] R. Xu, et al. Nat. Commun. 13, 6587 (2022)
[4] M. Ha, et al. Adv. Mater. 33, 2005521 (2021)
[5] E.S. Oliveros‐Mata, E. S., C. Voigt, et al. Adv. Mater. Technol. 2200227 (2022)