Low-cost (<€5), open-source, potential alternative to commercial spectrophotometers.

Spectrophotometry is a fundamental technique in many areas of science, with many applications and uses. The cost of spectrophotometers has acted as a barrier on the teaching and use of the technique. Here, we provide open-source plans to a 3D-printed cuvette holder with an interchangeable narrow-spectral bandwidth light-emitting diode (LED) block that can be used in conjunction with a smartphone's ambient light sensor (ALS) to perform spectrophotometry.

An Outlook on Physical and Virtual Sensors for a Socially Interactive Internet.

The Internet keeps changing at a rapid pace, driven mainly by the emerging concepts and applications that make it aware of the physical world and responsive to user context. The Internet of Things (IoT) concept is quickly giving way to more advanced and highly interactive environments that go well beyond the mere sensing of the physical world. Today, in addition to traditional electronic devices, IoT sensing/actuating includes both software and human-based entities.