The present invention relates to the use of a shrinkable biopolymer fiber as sensor. In a first embodiment, the sensor allows to determine the authenticity of a product. In a second embodiment, the sensor allows to determine the presence of a solvent. Further, the present invention relates to a method for determining the authenticity of a product. Furthermore, the present invention relates to a method for determining the presence of a solvent. In addition, the present invention relates to the use of a shrinkable biopolymer fiber for shaping an object. Moreover, the present invention relates to a method for shaping an object. Moreover, the present invention relates to the use of a shrinkable biopolymer fiber as suture material or wound dressing.
