Effects of Spent Coffee Grounds on Improvement of Resistive Switching Characteristics in Natural Rubber‐Based Memory

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 21; no. 32; pp. e2504260 - n/a
• Main Authors: Awais, Muhammad, Othman, Nadras, Shafiq, Mohamad Danial, Zhao, Feng, Cheong, Kuan Yew
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.08.2025
• Subjects: bio‐organic material; Functional groups; Low resistance; Memory devices; Natural rubber; Ohm's Law; resistive switching memory; spent coffee grounds; Voltage sweep rate; bio‐organic material; natural rubber; resistive switching memory; spent coffee grounds
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.202504260

The recent upsurge in environmental awareness provokes the widespread usage of green materials in sustainable electronic applications. Herein, the effects of spent coffee grounds (SCGs) on natural rubber (NR)‐based resistive switching (RS) memory are systematically investigated. This study presents the fabrication of a metal‐insulator‐metal (MIM) structure using NR incorporated with SCGs (0 to 8 wt.%) as a memristive layer and sandwiched between electrodes. A significant improvement in the ON/OFF ratio from 104 for pure NR to 107, read memory window increased from 2.03 to 2.45 V with improved stability even after 130 cycles of switching is achieved with the optimal concentration of SCGs (6 wt.%). The improved performance after the incorporation of SCGs is attributed to the introduction of key chemical functional groups (C═O, C═C) in the memristive film. By varying the viscosity of NR, bending of test structure, and voltage sweep rate, the effects of trap density and location on the RS performance are established. The RS mechanisms in high and low resistance states are dominated by space‐charge‐limited conduction and Ohm's law, respectively. This research manifests the potential of SCGs in improving the RS performance of bioorganic‐based memory devices. Role of spent coffee grounds (SCGs) (0–8 wt.%) in enhancing the resistive switching performance of natural rubber‐based memristive films. SGCs enrich natural rubber films with C═O, C═C, and COOH, and their functions related to resistive switching mechanisms are identified. Change of viscosity in natural rubber, test structure bending, and sweep rate on resistive switching linked to charge conduction and switching behavior. Optimized 6 wt.% SCGs device achieves an ON/OFF ratio of 107 and a read memory window of 2.45 V.