The TR Araña (Spanish, meaning "route tracing spider") is a robot that is claimed to remotely analyse the composition of the ground. The device was created by Chilean inventor Manuel Salinas and was reported to be able to operate at depths of up to 50 metres. It is widely believed by the scientific community to be a fraud.^[1]

This article includes a list of general references, but it lacks sufficient corresponding inline citations. (November 2009)

Answering a request by the Chilean Commission on Nuclear Energy, Salinas wrote the following paragraph:

"[The principle behind the robot is] The non linear integration of the basic unit of life conformation the way it is known; therefore and merely as a functional and explanatory concept, I detail that our device is the integration of highly sophisticated electronic components which are able to decipher the unanimity equation in the chaos theory in the context of an integral raised to the power of the radical exponent, based in the conformation of the species, the way they are known after 20,000 years of assisted evolution."

— Manuel Salinas^[2]

At a presentation at the Universidad Técnica Federico Santa María in Valparaíso, Chile, on 12 October 2005, Salinas gave fantastic and seemingly irrational theories to explain how his machine worked. Before an audience of students, physicists and engineers he offered inconsistent explanations. But after some questions by students (questions answered with a mix of science fiction and ignorance), professor and Doctorate in Physics Patricio Häberle spoke to the audience, thanking them for their patience and respect, but saying that the presentation would stop there, the University would neither support nor give space for it and that what the person (referring to Salinas) had talked about was not serious.^[3]

Salinas says that the robot bounces a nuclear signal off materials to search for specific atomic compositions.^{[citation needed]} Consensus exists among scientists that the technology Salinas says is used on the robot works^{[citation needed]} — but only to depths of 30 cm and anything beyond that, such as the dozens of meters he claims to be able to probe, would be considered a technological advance.

Salinas has refused to patent the machine, saying the technology is "an industrial secret."^{[citation needed]}