A fully functional auxetic electronic system for wearable applications

Soft, flexible, and stretchable devices have become widely used in wearable electronics such as health monitoring over the past decades. Despite the rapid development of flexible devices, silicon-based rigid components are still the mainstream in circuit and sensing technology because of their high performance and low cost. Origami-based circuits show promise in combining rigid electronic components and stretchable structures for better flexible electronic devices. In this project, we have the following missions:

  • Understanding from mathematics and mechanics of origami tessellations and addressing the technical challenges from electronics and manufacturing to facilitate the development of smart garments.

  • Developing the additive and micro-manufacturing for multi-functional and multi-scale devices (such as thermoelectric energy conversion devices) for monitoring human movement and health.

  • Developing the packaging technology for origami-inspired systems to get a fully functional auxetic (growable) electronic system for wearable applications.


Published paper link: https://www.nature.com/articles/s41528-021-00099-8

A Miura-ori structured flexible microneedle array electrode

Highly reliable signal recording with low electrode-skin impedance makes the microneedle array electrode (MAE) a promising candidate for biosignal sensing. However, when used in long-term health monitoring for some incidental diseases, flexible microneedles with perfectly skin-tight fit substrates lead to sweat accumulation inside, which will not only affect the signal output but also trigger some skin allergic reactions.

Here, a flexible MAE on a Miura-ori structured substrate is proposed and fabricated with two-directional in-plane bendability. The results from the comparison tests show enhanced performance in terms of (1) the device reliability by resisting peeling off of the metal layer from the substrate during the operation and (2) air ventilation, achieved from the air-circulating channels, to remove sweat. Bio-signal recordings of electrocardiography (ECG), as well as electromyography (EMG) of the biceps brachii, in both static and dynamic states, are successfully demonstrated with superior accuracy and long-term stability, demonstrating the great potential in health monitoring applications.


Published paper link: https://www.nature.com/articles/s41378-021-00259-w