This review provides an overview of the current state‐of‐the‐art of the emerging field of flexible multifunctional sensors for wearable and robotic applications. In these application sectors, there is a demand for high sensitivity, accuracy, reproducibility, mechanical flexibility, and low cost. The ability to empower robots and future electronic skin (e‐skin) with high resolution, high sensitivity, and rapid response sensing capabilities is of interest to a broad range of applications including wearable healthcare devices, biomedical prosthesis, and human–machine interacting robots such as service robots for the elderly and electronic skin to provide a range of diagnostic and monitoring capabilities. A range of sensory mechanisms is examined including piezoelectric, pyroelectric, piezoresistive, and there is particular emphasis on hybrid sensors that provide multifunctional sensing capability. As an alternative to the physical sensors described above, optical sensors have the potential to be used as a robot or e‐skin; this includes sensory color changes using photonic crystals, liquid crystals, and mechanochromic effects. Potential future areas of research are discussed and the challenge for these exciting materials is to enhance their integration into wearables and robotic applications.

This paper reports a self-powered, flexible, piezo-and pyro-electric hybrid nanogenerator (NG) device that can be fixed on different locations of human skin for detecting static and dynamic pressure variations and can also monitor temperature fluctuations during the respiration process. An efficient and cost-effective fabrication strategy has been developed to create electrospun poly(vinylidene fluoride) (PVDF)/ graphene oxide (GO) nanofibers, which are used to create a highly sensitive wearable pressure sensor and pyroelectric breathing sensor. The sensor can accurately and rapidly detect pressures as low as 10 Pa with a high sensitivity (4.3 V/kPa), a key performance indicator for wearable sensors. Importantly, the sensor exhibits a high sensitivity to bending and stretching by finger, wrist, and elbow. The pressure sensor is also highly sensitive to vocal vibrations when attached to the human throat. The device can generate a maximum output power density of ∼6.2 mW/m 2 when subjected to a compressive stress, which enhances its range of applications. Moreover, it is demonstrated that doping with GO improves the pyroelectric energy harvesting and sensing performance of the device under repeated temperature fluctuations. The PVDF/GO-based nanogenerator has a maximum pyroelectric output power density of ∼1.2 nW/m 2 and can sense temperature changes during respiration, which makes it promising as a pyroelectric breathing sensor. It is demonstrated that processing of the PVDF-GO self-powered multifunctional pressure and pyroelectric breathing sensor can be up-scaled for fabricating compact and high-performance electronic skins for application in health monitoring, motion detection, and portable electronics.

This paper demonstrates the significant benefits of exploiting highly aligned porosity in piezoelectric and pyroelectric materials for improved energy harvesting performance.

A major challenge affecting the outcomes of patients with lung cancer is the development of acquired radioresistance. However, the mechanisms underlying the development of resistance to therapy are not fully understood. Here we discovered that ionizing radiation (IR) induces phosphorylation of JAK2 and STAT3 in association with increased levels of Bcl2/Bcl-XL in various human lung cancer cells. To uncover new mechanism(s) of radioresistance of lung cancer, we established lung cancer cell model systems with acquired radioresistance. As compared to radiosensitive parental lung cancer cells (i.e. A549, H358 and H157), the JAK2/STAT3/Bcl2/Bcl-XL survival pathway is significantly more activated in acquired radioresistant lung cancer cells (i.e. A549-IRR, H358-IRR and H157-IRR). Higher levels of STAT3 were found to be accumulated in the nucleus of radioresistant lung cancer cells. Niclosamide, a potent STAT3 inhibitor, can reduce STAT3 nuclear localization in radioresistant lung cancer cells. Intriguingly, either inhibition of STAT3 activity by niclosamide or depletion of STAT3 by RNA interference reverses radioresistance in vitro. Niclosamide alone or in combination with radiation overcame radioresistance in lung cancer xenografts. These findings uncover a novel mechanism of radioresistance and provide a more effective approach to overcome radioresistance by blocking the STAT3/Bcl2/Bcl-XL survival signaling pathway, which may potentially improve lung cancer outcome, especially for those patients who have resistance to radiotherapy.