ICMCTF 2021 Virtual Conference Session LI-MoM1: Coatings for Flexible Electronics and Bio Applications Live Session

Rapid, on-site assessment is highly desirable in the fields of both medical treatment and novel robotics. To achieve this goal, my group's research aims to develop low-cost, flexible, large-area sensor devices for different health and environmental applications. In this presentation, we discuss case studies using similar pressure sensors for two different point-of-use applications:

1) Motor skills characterization. There is no objective metric for evaluating motor skill training progress in autistic children, and current assessments rely on qualitative surveys. We have fabricated an instrumented glove with touch sensors on textile for finger tapping patterns characterization. This glove could find future use for characterizing motor skills of people suffering from autism, Parkinson’s disease, epilepsy seizures, and other neurological motor disorders.

2) Robotic sensors for simultaneous pressure and chemical detection. There is an urgent need of sensor technologies to monitor hazardous materials for security and environmental applications. Rapid on-site detection of chemicals through remote robotic sampling is highly desired to avoid placing people at exposure risks. We have combined printed chemical and pressure sensors together on disposable gloves, and demonstrated successive simultaneous tactile sensing and pesticide detection in a point-of-use platform that is scalable and economical.

Portable consumer electronics necessitates functional elements to be lightweight, flexible, and wearable [1-3]. The unique possibility to adjust the shape of the devices offered by this alternative formulation of the electronics provides vast advantages over the conventional rigid devices particularly in medicine and consumer electronics. There is already a remarkable number of available flexible devices starting from interconnects, sensing elements towards complex platforms consisting of communication and diagnostic components.

We developed shapeable magnetoelectronics [3] – namely, flexible [4,5], printable [6], stretchable [7] and even imperceptible [8-12] magnetosensitive elements, which were completely missing in the family of flexible electronics, e.g. for smart skin applications.

Here, we will review technological platforms allowing to realize not only mechanically imperceptible electronic skins, which enable perception of the geomagnetic field (e-skin compasses) [10], but also enable sensitivities down to ultra-small fields of sub-50 nT [11]. These devices allow humans to orient with respect to earth’s magnetic field ubiquitously. Furthermore, biomagnetic orientation enables novel interactive devices for virtual and augmented reality applications. We showcase this by realizing touchless control of virtual units in a game engine using omnidirectional magnetosensitive skins. This concept was further extended by demonstrating a compliant magnetic microelectromechanical platform (m-MEMS), which is able to transduce both tactile (via mechanical pressure) and touchless (via magnetic field) stimulations simultaneously and discriminate them in real time [12]. This is crucial for interactive electronics, human-machine interfaces, but also for the realization of smart soft robotics with highly compliant integrated feedback system as well as in medicine for physicians and surgeons.

[1] M. G. Lagally, MRS Bull. 32, 57 (2007).

[2] J. A. Rogers et al., Nature 477, 45 (2011).

[3] D. Makarov et al., Appl. Phys. Rev. 3, 011101 (2016).

[4] M. Melzer et al., Adv. Mater. 27, 1274 (2015).

[5] N. Münzenrieder et al., Adv. Electron. Mater. 2, 1600188 (2016).

[6] D. Karnaushenko et al., Adv. Mater. 27, 880 (2015).

[7] M. Melzer et al., Adv. Mater. 27, 1333 (2015).

[8] M. Melzer et al., Nat. Commun. 6, 6080 (2015).

[9] G. S. Canon Bermudez et al., Science Advances 4, eaao2623 (2018).

[10] G. S. Canon Bermudez et al., Nature Electronics 1, 589 (2018).

[11] P. N. Granell et al., npj Flexible Electronics 3, 3 (2019).

[12] J. Ge et al., Nature Commun. (2019). doi:10.1038/s41467-019-12303-5

Titanium implants are used widely in orthopedic and dental applications. Their primary function is to integrate with the surrounding bone and provide biomechanical support. Although, several surface modification technologies have been adopted to improve the osteointegration, it remains elusive in normal and more so in diseased individuals. Here, we propose a methodology to apply a biologically active natural extracellular matrix (ECM) coating to implants. Titanium implant surfaces were coated with a natural osteogenic ECM from human bone marrow derived mesenchymal stem cells (HMSCs) using a decellularization technique. The ECM coating was verified quantitatively and qualitatively by immunological characterization. The enhanced ability of coated surfaces to promote attachment, proliferation and osteogenic differentiation of HMSCs was evaluated in vitro quantitatively and qualitatively by means of proliferation assays, live cell imaging and qPCR analyses. Osteointegration was evaluated in vivo in a rat tibial model. Results indicated that the procedure resulted in an even coating of ECM on the implants. In vitro studies indicated that the coated implants promoted enhanced attachment, proliferation and osteogenic differentiation of HMSCs. In vivo experiments revealed enhanced bone formation around coated implants as observed by m CT analysis. Overall, these results indicate that coating titanium implant surfaces with a biomimetic ECM can enhance their functionality by generating a bioactive surface and promoting enhanced osteointegration.