UAV icing is a severe challenge that has only recently shifted into the focus of research. Today, there are no mature icing mitigation technologies for UAVs, except for the largest fixed-wing drones. We are working on the development of an electro-thermal icing protection technology called D•ICE for medium-sized fixed-wing UAVs. As part of the design process, an experimental test campaign at the Cranfield icing wind tunnel has been conducted. This paper describes the icing protection system and shares experimental results on its capability for icing detection and anti-icing. Icing detection is based on an algorithm evaluating temperature signals that are induced on the leading-edge of the wing. A baseline signal is generated during dry (icing cloud off) conditions and compared to a signal during wet (icing cloud on) conditions. Due to significant differences in the heat transfer regime, the system can differentiate between these two states. The experiments show that our system can reliably detect icing conditions based on this principle. Furthermore, the anti-icing capability of the system is proven for two icing cases. The minimal required heat flux to keep the surface ice-free was obtained by gradually reducing power supply to the heating zones until icing could be detected. These experimental results were compared to FENSAP-ICE simulations. The test campaign includes a successful fully-autonomous run, where the system automatically detected icing and initiated suitable anti-icing measures.

An essential part of any space in which physical prototyping and prototype-driven product development is being conducted is the education of its users in the necessary skills to fully utilise the material resources of the space. This paper describes how two different skills were transferred between five projects in our research laboratory, TrollLABS. Based on the observed skill-transfers in the production of PCBs and use of RF-communication in mechatronics projects certain tendencies emerged: How the use of forced vocal experience sharing; And in-person transferring of skills has impacted the acquired skills of the learner. The observations further show that through the guidance of a more experienced user the learner is able to make "skill-jumps": Intermediate skill steps, as well as underlying detailed knowledge, are skipped and the learner is able to reach a high skill level in a shorter time than the original acquirer of the skill. Furthermore, skills are retained in the space through cross-generational collaboration and communication. This article aims to share these insights and provide a starting point for answering some of the challenges of modern maker spaces.

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Pulse detection has in recent years received extensive attention in physiological health monitoring, and continuous blood pressure estimation models based on pulse waveform analysis have shown great promises. Two widely used technologies for noninvasive detection of the pulse waveform are photoplethysmography and tonometry. Although the signals from PPG and tonometry are rooted in different physiological mechanisms, the technologies are typically used separately. The simplistic approach of estimating cardiovascular responses based on single sensor sources is discorrelated with the complexity of the human body. To acknowledge this, we have developed a low-cost, low-power sensor prototype combining PPG and force-sensing capabilities. The proposed solution is able to accurately detect the pulse waveform, both optically and tactually, in addition to estimating the sensor interface pressure. We hypothesize that the combined solution can be used to ameliorate one or more of the challenges associated with the separate technologies in physiological monitoring, and thus potentially give continuous pulse waveform based blood pressure estimation models valuable additional inputs, ultimately leading to increased estimation accuracies and measurement confidence.

In nature, fish use sensory input to feel and adapt to flow conditions. Creating solutions that mimic these capabilities need flexible and sensitive sensor solutions. In this paper we use readily available carbon fibers as a conductive filler in a rubber silicone matrix to create a piezoresistive material, capable of sensitively gathering frequency information of small, repeatedly, applied forces. The material is easily cast into a flexible hydrofoil and suspended in two alternating vortex streets flowing at 0.04m/s and 0.1m/s. The gathered data is used to examine the shedding frequency of the vortex streets where the sensors are able to detect frequencies in proximity to the expected frequencies of the flow conditions.