A membrane enclosed fluid diffusion system for insect attractants and repellents, auto thermostatic heaters, and chemical delivery using an additive and/or selectively permeable membrane that interacts with the enclosed fluid to maintain steady delivery rates over a range of temperature and humidity. Systems can be formed with permeable membranes, impermeable membranes, chemical hydrates, wicks, scent fluids, fuel fluids, catalytic heaters, energy conversion devices, visible images, infrared images, trapping systems, sound systems, electronics, and apparel. The device results in efficient and effective devices for mosquito control drug delivery, and portable heaters.