Lightweight design, energy efficiency and heat management are the core themes of the Smart Forvision concept, a collaboration between Smart and materials specialist BASF which will be unveiled at the Frankfurt motor show later this month.

Forvision's innovations include:

• transparent organic solar cells
• transparent and energy-saving light-emitting diodes
• infrared-reflective films and coatings
• high-performance insulation foams
• the first all-plastic wheels

"With the forvision smart is doing justice to its role as Daimler's think tank for urban mobility. We are presenting numerous world premieres that make uncompromising electric mobility possible," said Dr. Annette Winkler, head of Smart.

"Cars of the future need materials and technologies which reduce energy consumption whilst also increasing the range and level of comfort. Our innovations make a decisive contribution to this", says Dr. Christian Fischer, head of BASF Polymer Research.

According to Smart, the combination of these technologies can result in an increase of electric vehicle range of up to 20%.

Smart Forvision has hexagonal solar cells which generate engine and allow ambient light through.

Transparent solar cells and OLED interior illumination

The transparent hexagons on the roof of the Smart Forvision are transparent solar cells based on organic dyes which are are light-activated. Even in low light they generate enough energy to power the Smart's ICE system and three fans which assist with climate management in the vehicle interior. If the vehicle is standing in the sun the ventilation is permanently operated with the help of these solar cells, keeping the car cool.

Under the solar cells are transparent OLEDs (organic light-emitting diodes) which provide interior lighting. The OLEDs consume less than half as much energy as conventional energy-saving lamps.

All-plastic wheels and carbon fibre panels save weight

The Smart Forvision is fitted with the first all-plastic wheel said to be "suitable for high-volume production". The wheel was developed by BASF using a new high-performance composite material which has long reinforcing fibres to improve its mechanical properties. The result is a wheel which saves 3kg and has excellent thermal and chemical stability, dynamic strength, toughness and good continuous operating characteristics.

The doors are made of carbon fibre reinforced epoxy resin, giving a weght saving of 50% compared to steel or 30% compared to aluminium. The resins developed by BASF have short hardening times, which makes them suitable for high production volumes.

Innovative interior materials provide active and passive heat management

A light, self-supporting plastic shell forms the basis for seats which are light in weight and play a role in temperature management. Reacting to studies which have shown that the body only absorbs heat efficiently through certain contact points, the Forvision uses "e-textiles" (thin fabrics with custom-tailored conductive coatings) to replace conventional seat heating. E-textiles are also found in the door armrest.

The BASF foam which pads the seats is 10-20% lighter than existing materials and in manufacture it can provide different degrees of hardness in different areas of the upholstery in a single work operation.

Smart Forvision is packed with innovative materials which make more efficient use of energy, together contributing to an increase in EV range of up to 20%.

High-performance coatings and insulation regulate interior temperature

BASF infrared-reflective film has been applied to the windscreen and side windows to reduce solar gain - the heating of the interior in sunny weather. This kind of heat shielding has not been previously used for automotive applications. The film has high transparency in the visible range, so it can also be applied to tinted windows without visibility problems and guarantees an unprecedented level of reflection of sunlight and heat. This non-metal film reflects only the infrared rays of the sun - unlike metallized films already in use, which can reject radio signals and hamper the use of mobile equipment such as phones and navigation systems.

The high-performance foams insulate body panels to keep the vehicle  cool in summer and warm in winter. Thanks to their high efficiency even in a small thickness, they can be fitted everywhere in the vehicle.

The Forvision's external finish is infrared-reflective, and special BASF colour pigments ensure that even darker colours will reflect rather than absorb heat radiation, giving a 20degC reduction in paint surface temperature in hot weather. The finish incorporates glass flakes for a gleaming metallic look.