Accelerated Self-Sintering Mechanism And Device Application Of Degradable Transient Conductive Composites

Biodegradable transient electronic device is a new type of electronic device in the developing route of "More-than-Moore" of the post-Moore era of integrated circuits.Its main feature is that after a controllable or predictable operation period,the material composition or device function can be partially degraded or completely degraded by physical disintegration or chemical reaction.Therefore,transient electronics offers a wide application prospect in biomedical engineering,hardware security,green electronics and other fields.The preparation of degradable transient electronic devices is mainly based on biocompatible and biodegradable inorganic and/or organic materials.Biodegradable organic materials are highly sensitive to temperature,humidity and organic solvents,so it is a great challenge to prepare biodegradable transient electronic devices using traditional micro-nano processing technology.Degradable conductive composite materials that are based on printed electronics technology provide a lowcost,efficient and large-scale production scheme for the preparation of degradable transient electronic devices.In recent years,researchers have made unremitting efforts to develop highly conductive,safe and reliable degradable conductive composite materials,and put forward various sintering methods to greatly improve the conductivity of materials,which can be applied in degradable transient printed circuits.However,there are still many limitations in the preparation and practical application of biodegradable conductive composites,such as the introduction of potentially harmful organic solvents,complex sintering process,and single transience mechanism.Aiming for addressing the existing important challenges in this research field,this paper proposes a method to prepare high conductivity degradable molybdenum/wax conductive composite.The self-sintering and accelerated self-sintering of degradable molybdenum/wax conductive composite are systematically studied,and the accelerated self-sintering mechanism is clarified.Finally,a multimodal transient electronic device with biodegradation,organic solvent degradation and thermally-triggered transience was developed.The fabricated biodegradable molybdenum/wax conductive composites developed in this paper mainly includes the following advantages and unique properties:1)the solvent-free preparation method of conductive composites;2)the firstly demonstrated self-sintering behavior of molybdenum/wax conductive composite;3)the propose of accelerating self-sintering method to improve conductivity and electrical stability;4)rehealable properties of molybdenum/wax conductive composite;5)verification of multi-mode transient electronic devices and integrations.In this paper,the internal mechanism of the self-sintering behavior of molybdenum/wax conductive composite was elucidated by controlling variables,and both positive effect(accelerated self-sintering dominant)and negative effect(degradation dominant)of phosphate buffer solution treatment on the conductivity of molybdenum/wax conductive composite were systematically studied.Finally,several application examples of degradable molybdenum/wax conductive composite materials in repairable electronic devices,multimodal transient electronic devices and integration are presented,including resistive temperature sensors,resistive stress sensors,capacitive distance sensors,and low-pass filters.