openQCM is a highly-sensitive microbalance with a wide-range of applications in chemistry, biology and material science.
Created by a group of Italian physicists, openQCM is a fully open-source quartz crystal microbalance project built around the versatile Arduino Micro (ATmega32U4). Impressively, the gadget is capable of weighing mass deposition down to one billionth of gram.
For those unfamiliar with the piezoelectric devices, a QCM is an extremely sensitive mass sensor capable of measuring mass changes in the nanograms. When an object is placed on the sensor’s surface, the fluctuations in the crystal’s resonant frequency are detected and used to determine its mass in a variety of experimental conditions. In this case, the openQCM was designed for use in air, liquid and vacuum, and features a sensitivity of 700 picograms.
Novaetech S.r.l. initially developed openQCM with the emergent principles of the open-source hardware movement in mind. Team member Marco Mauro notes that while open hardware has already made an impact across a wide-range of segments, when it comes to scientific applications, its potential is even greater.
“openQCM is the first open hardware quartz crystal microbalance with applications in a wide range of scientific fields, such as chemical and biological sensing, material science,” the team writes.
openQCM is based on an Arduino Micro and is powered via USB connection. This enables users to hack the timer counter on the on-board ATmega32U4 to measure the quartz crystal frequency variations using its 16Mhz processor clock. Its creators also designed an Arduino Micro shield with an embedded quartz crystal oscillator driver circuit and a temperature sensor. As noted, this plays an integral role in checking the thermal stabilization of the device. The output of the driver is relayed to the Arduino timer counter, while the analog value of the temperature sensor is fed to the board’s analog pin. This configuration allows researchers to measure quartz crystal frequency with a resolution of 1Hz.
In an effort to reduce costs without sacrificing quality, the team decided to 3D print the openQCM prototypes using the SLS process. Embodying true Maker spirit, this lets everyone modify and print their own enclosure.
“openQCM belongs to a new generation of innovative smart sensor which boast high resolution and ultra high mass sensitivity. The open source strategy made the creation of openQCM available at low cost which represents a bit fraction of the cost of similar scientific products,” the team concludes.
Despite its affordability and ease-of-use, its creators assure its accuracy and stability is fully comparable with most common scientific devices available on the market today. Interested in learning more? Head over to openQCM’s official page here.