Tag Archives: biology

Graphene’s Consequences On Human Health

As the drive to commercialise graphene continues, it is important that all safety aspects are thoroughly researched and understood. The Graphene Flagship project has a dedicated Work Package studying the impact of graphene and related materials on our health, as well as their environmental impact. This enables safety by design to become a core part of innovation.

Researches and companies are currently using a range of materials such as few layered graphene, graphene oxide and heterostructures. The first step to assess the toxicology is to fully characterise these materials. This work overviews the production and characterisation methods, and considers different materials, which biological effects depend on their inherent properties.


One of the key messages is that this family of materials has varying properties, thus displaying varying biological effects. It is important to emphasize the need not only for a systematic analysis of well-characterized graphene-based materials, but also the importance of using standardised in vitro or in vivo assays for the safety assessment,” says Bengt Fadeel, lead author of this paper working at Graphene Flagship partner Karolinska Institutet, Sweden.

This review correlates the physicochemical characteristics of graphene and related materials to the biological effects. A classification based on lateral dimensions, number of layers and carbon-to-oxygen ratio allows us to describe the parameters that can alter graphene’s toxicology. This can orient future development and use of these materials,” explains Alberto Bianco, from Graphene Flagship partner CNRS, France and deputy leader of the Graphene Flagship Work Package on Health and Environment.

Source: https://graphene-flagship.eu/

A self-powered heart monitor taped to the skin

Scientists in Japan have developed a human-friendly, ultra-flexible organic sensor powered by sunlight, which acts as a self-powered heart monitor. Previously, they developed a flexible photovoltaic cell that could be incorporated into textiles. In this study, they directly integrated a sensory device, called an organic electrochemical transistor—a type of electronic device that can be used to measure a variety of biological functions—into a flexible organic solar cell. Using it, they were then able to measure the heartbeats of rats and humans under bright light conditions.

Self-powered devices that can be fit directly on human skin or tissue have great potential for medical applications. They could be used as physiological sensors for the real-time  or the real-time monitoring of heart or brain function in the human body. However, practical realization has been impractical due to the bulkiness of batteries and insufficient power supply, or due to noise interference from the electrical supply, impeding conformability and long-term operation.

The key requirement for such devices is a stable and adequate energy supply. A key advance in this study, published in Nature, is the use of a nano-grating surface on the light absorbers of the solar cell, allowing for high photo-conversion efficiency (PCE) and light angle independency. Thanks to this, the researchers were able to achieve a PCE of 10.5 percent and a high power-per-weight ratio of 11.46 watts per gram, approaching the “magic number” of 15 percent that will make organic photovoltaics competitive with their silicon-based counterparts.

To demonstrate a practical application, sensory devices called organic electrochemical transistors were integrated with organic solar cells on an ultra-thin (1 μm) substrate, to allow the self-powered detection of heartbeats either on the skin or to record electrocardiographic (ECG) signals directly on the heart of a rat. They found that the device worked well at a lighting level of 10,000 lux, which is equivalent to the light seen when one is in the shade on a clear sunny day, and experienced less noise than similar devices connected to a battery, presumably because of the lack of electric wires.

According to Kenjiro Fukuda of the RIKEN Center for Emergent Matter Science, “This is a nice step forward in the quest to make self-powered medical monitoring devices that can be placed on human tissue. There are some important remaining tasks, such as the development of flexible power storage devices, and we will continue to collaborate with other groups to produce practical devices. Importantly, for the current experiments we worked on the analog part of our device, which powers the device and conducts the measurement. There is also a digital silicon-based portion, for the transmission of data, and further work in that area will also help to make such devices practical.

The research was carried out by RIKEN in collaboration with researchers from the University of Tokyo.

Source: http://www.riken.jp/