Abstract: Methods and devices for improved membrane-based microcalorimeters are disclosed. The sample mixing speed or “temporal addenda” of the calorimeter can be improved using membranes with patterned hydrophilic and hydrophobic regions, oscillating droplet squeezing methods, and textured membrane surfaces with ridges designed to facilitate rapid mixing. The thermal coupling between the membranes and the other calorimetric addenda can be minimized by exposing the back side of the calorimetric membrane to a vacuum, while keeping the front side exposed to a humidified environmental chamber. Specially shaped, membrane associated heat-transfer-elements can help the system accurately monitor substantial portions of the sample. These elements, in conjunction with the position of the edge of the sample, can be designed to minimize inaccuracy due to edge evaporation effects.

Abstract: In one embodiment, a microcalorimeter system includes a first microfluidic channel coupling a calorimeter with a sample chamber. A second microfluidic channel couples the calorimeter with a waste chamber. An inertial pump includes a fluid actuator integrated asymmetrically within the first microfluidic channel, and the fluid actuator is capable of selective activation to pump fluid from the sample chamber to the calorimeter and from the calorimeter to the waste chamber through the first and second microfluidic channels, respectively.

Abstract: In one aspect, provided herein is a single crystal silicon microcalorimeter, for example useful for high temperature operation and long-term stability of calorimetric measurements. Microcalorimeters described herein include microcalorimeter embodiments having a suspended structure and comprising single crystal silicon. Also provided herein are methods for making calorimetric measurements, for example, on small quantities of materials or for determining the energy content of combustible material having an unknown composition.