Visible light communication systems can be used in a wide variety of applications, from driving to home automation. The use of wearables can increase the potential applications in indoor systems to send and receive specific and customized information. We have designed and developed a fully organic and flexible Visible Light Communication system using a flexible OLED, a flexible P3HT:PCBM-based organic photodiode (OPD) and flexible PCBs for the emitter and receiver conditioning circuits. We have fabricated and characterized the I-V curve, modulation response and impedance of the flexible OPD. As emitter we have used a commercial flexible organic luminaire with dimensions 99 × 99 × 0.88 mm, and we have characterized its modulation response. All the devices show frequency responses that allow operation over 40 kHz, thus enabling the transmission of high quality audio. Finally, we integrated the emitter and receiver components and its electronic drivers, to build an all-organic flexible VLC system capable of transmitting an audio file in real-time, as a proof of concept of the indoor capabilities of such a system.

Blue viologen-based electrochromic devices on glass substrates were constructed with different internal active layer thickness by means of a thermoplastic spacer (DuPontTM surlyn1702). Optical measurements, chronoamperometry, and cyclic voltammetry (CV) were the techniques used for characterization. Coloration properties such as switching times for coloring and bleaching processes, coloration efficiency, and effective charge density, previously studied for a single device, are now obtained for several devices with different thicknesses. Dependence on thickness in the response times and in voltage-dependent parameters of device equivalent electric circuit model was studied in previous works. In this paper, some of those parameters, such as Warburg diffusion, double-layer capacitance, and charge transfer resistance, obtained with electrochemical impedance spectroscopy, are related with the coloration properties and their dependence on the thickness obtained by the aforementioned chronoamperometric and CV characterization.

Purpose: To evaluate the potential clinical usability of a new prototype of ophthalmic blue light filters developed by using electrochromic technology in pseudophakic patients complaining of glare. Methods: A prototype of electrochromic device was developed, with a specific frame that enclosed an electronic driver that allowed personalizing its function for each patient. A prospective, observational case series study was performed to test it. Five patients who had undergone cataract surgery with clear intraocular lenses and complaining of glare were included in the study. Main outcome measures were the results obtained in the satisfaction questionnaire that was delivered to patients. Then, visual acuity, contrast sensitivity, and reading ability data were evaluated with and without the prototype under different lighting conditions and different modes of the prototype after a complete month of use. Lens transmittance was also measured. Results: Visual acuity, contrast sensitivity and reading function did not change significantly with prototype use. The main activity for which the prototype was used was walking. Only one patient found that the dimming level was insufficient. No patients reported variable discomfort when passing tunnels, not sufficiently clear indoors, or put on and remove discomfort. The lenses slightly decreased their transmittance at the end of the study. Conclusion: Glasses based on electrochromic technology may be acceptable for outdoor/indoor use and for distance–near vision. Future studies with larger samples must be conducted to confirm the clinical usability of these glasses.

The aim of the chapter is to review the most recent advances in electro-optical technologies applied to visually disabled people. The World Health Organization (WHO) estimates that the number of people in the world with some kind of visual impairment is 285 million, with 246 million of these persons in a partially sighted or Low Vision (LV) condition. The top three causes of visual impairment are uncorrected refractive errors, cataracts and glaucoma, followed by age-related macular degeneration. On the other hand, Head Mounted Displays or electro-optical materials used in liquid crystal or electrochromic devices can be used in technical aids for LV. In this chapter, the authors review how disabled people receive real world information using these new technologies, how the recently developed electro-optical technical aids can improve visual perception, and how these LV aids do work, from a technological point of view.