We are developing a smart chin cup system for real-time orthodontic compliance monitoring using laser-induced graphene (LIG) sensors fabricated by CO2 laser processing.

A flexible LIG bending sensor is directly formed on a Kevlar substrate and integrated into the curved side region of a chin cup appliance. When the chin cup is worn or removed, changes in the appliance's bending deformation produce distinct resistance signals, enabling real-time monitoring of the patient’s wearing status.

The sensor is connected to a compact, battery-powered wireless circuit, allowing continuous and quantitative tracking of chin cup usage during daily activities. This approach provides a lightweight, flexible, and minimally intrusive platform for objectively evaluating orthodontic treatment compliance, with potential applications in personalized digital orthodontic care.

(In collaboration with Prof. Young-Jin Kim's group in KAIST and Prof. Sang Wook Kang’s research group at KHU.)

We are developing a smart denture with temperature-sensing capabilities using selective laser ablation technology with a femtosecond (fs) laser.

A thin gold film is deposited onto PMMA, a common denture material, and then selectively etched using laser processing. The processed sensor is then integrated into a 3D-printed denture. This system offers high stability and long-term wearability, making it easier for elderly individuals and patients to monitor their body temperature and food consumption activity.

Additionally, we fabricate a tongue pressure sensor by first creating laser-induced graphene (LIG) on a polyimide (PI) film using a UV nanosecond (ns) laser. The LIG is then transferred onto PDMS and embedded into a 3D-printed denture.

We have successfully fabricated LIG on Kevlar, a material widely known for its bulletproof carbon fiber properties, using laser irradiation.

Leveraging this LIG-Kevlar platform, we have developed a range of wearable electronic applications, including voice recognition, body temperature monitoring, body motion sensing, ECG signal detection, and micro-supercapacitor (MSC) integration for LED activation. 

Through these innovations, we demonstrate the potential of LIG-based wearable electronics, paving the way for advanced, multifunctional, and flexible sensor technologies.

(In collaboration with Dr. Soongeun Kwon at KIMM.)