In the past few decades, electronic skin has attracted global attention because of its broad application prospects in intelligent robots, health monitoring, wearable devices, and human-computer interaction.

The so-called electronic skin is a new electronic device that simulates the human skin to experience external stimuli (pressure, temperature, humidity) through the integration and feedback of electrical signals. Among the various perception functions of electronic skin, the tactile perception function is particularly important.

Recently, a team from the Shanghai Institute of Advanced Studies of the Chinese Academy of Sciences has made important progress in the research of 3D printing flexible tactile sensor devices based on carbon materials. The team’s research results were published in the international journal ACS Applied Materials & Interfaces with the title “A Highly Sensitive Flexible Tactile Sensor Mimicking The Microstructure Perception Behavior of Human Skin”.

The corresponding author of the paper is researcher Zeng Xiangqiong, Shanghai Institute for Advanced Study, Chinese Academy of Sciences, and the first author is Dr. Haihang Wang from Shanghai Institute for Advanced Study. This work was funded by the Shanghai Natural Science Foundation of China.

In this latest study, the research team creatively micro-division polydimethylsiloxane (PDMS) by simulating the structure and sensing mechanism of human skin The ball and graphene are combined to design a new type of multifunctional electronic skin with fingerprint microstructure; a method for preparing a flexible sensor by 3D printing of graphene-PDMS microsphere ink is proposed.

The specific printing principle is that the research team uses the emulsification method to prepare PDMS microspheres, and coats the PDMS microspheres with an uncrosslinked PDMS-graphene mixed solution; the prepared graphene-PDMS microsphere ink can A three-dimensional structure is formed by extrusion through a nozzle, and formed by thermal curing.

The research team found through sensor performance research that the constructed electronic skin sensor not only has a sensitive response to pressure, but also can effectively feedback the magnitude of friction; using the sensor’s characteristics Different micron roughness can be distinguishedThe surface of the object, so as to realize the effective distinction and recognition of the microscopic morphology, hardness and other information of the surface of the object.

Through wind load experiments, the research team further verified that the constructed graphene-PDMS microsphere tactile sensor also has an effective response to gas and other fluids.

The above research results show that the graphene-PDMS microsphere tactile sensor built by the team can not only be used for the detection of different roughness surfaces, but also for airflow monitoring , Sound detection, etc.

The research team believes that this work provides a new way for wearable sensing and new ideas for the development of electronic skin.

Article link: https://pubs.acs.org/doi/full/10.1021/acsami.1c04079.