Highly transient and recyclable MoS2/PVA pressure sensor for sustainable healthcare and consumer electronic applications

Abstract

The advent of electronic gadgets has brought convenience to daily life; however, it has also contributed to the proliferation of electronic sensors, exacerbating the issue of electronic waste (e-waste). Previous efforts toward transient electronics aimed at addressing e-waste have faced challenges due to material wastage. To overcome these limitations, it would be beneficial to develop a process wherein transient electronics are reusable. In this study, a transient pressure sensor was fabricated using MoS₂ and PVA, and its degradation in an aqueous medium was subsequently demonstrated. The MoS₂, which served as the active material, was recovered after degradation and reused for the fabrication of another pressure sensor. Electrical tests on the sensor demonstrated its piezoresistive nature, with the device capable of detecting various pressures in the range of 1–3 kPa, exhibiting a sensitivity of 0.87 kPa⁻¹. A cyclic test was also conducted for 1200 cycles, revealing excellent durability. Moreover, the sensor maintained stable performance over three months without any loss in electrical properties. The fabricated sensor was employed in real-time applications, such as detecting the radial artery pulse (hand), carotid artery pulse (neck), and varying air pressures from a syringe bulb, and it was also used as directional keys for a gaming console. The MoS₂/PVA sensor dissolved completely within 300 s. The performance of the recycled MoS₂/PVA sensor was compared with that of the original MoS₂/PVA sensor, showing negligible differences. The successful demonstration of a MoS₂/PVA-based transient and recyclable pressure sensor holds immense potential for future IoT applications.