Nanocalorimetry using microscopic optical wireless integrated circuits.

We present in situ calorimetry, thermal conductivity, and thermal diffusivity measurements of materials using temperature-sensing optical wireless integrated circuits (OWiCs). These microscopic and untethered optical sensors eliminate input wires and reduce parasitic effects. Each OWiC has a mass of ∼100 ng, a 100-µm-scale footprint, and a thermal response time of microseconds. We demonstrate that they can measure the thermal properties of nearly any material, from aerogels to metals, on samples as small as 100 ng and over thermal diffusivities covering four orders of magnitude. They also function over a broad temperature range, and we present proof-of-concept measurements of the thermodynamic phase transitions in both liquid crystal 5CB and gadolinium.

Using stakeholder insights to enhance engagement in PhD professional development.

There is increasing awareness of the need for pre- and post-doctoral professional development and career guidance, however many academic institutions are only beginning to build out these functional roles. As a graduate career educator, accessing vast silos and resources at a university and with industry-partners can be daunting, yet collaboration and network development are crucial to the success of any career and professional development office. To better inform and direct these efforts, forty-five stakeholders external and internal to academic institutions were identified and interviewed to gather perspectives on topics critical to career development offices. Using a stakeholder engagement visualization tool developed by the authors, strengths and weaknesses can be assessed. General themes from interviews with internal and external stakeholders are discussed to provide various stakeholder subgroup perspectives to help prepare for successful interactions. Benefits include increased engagement and opportunities to collaborate, and to build or expand graduate career development offices.

Microscopic sensors using optical wireless integrated circuits.

We present a platform for parallel production of standalone, untethered electronic sensors that are truly microscopic, i.e., smaller than the resolution of the naked eye. This platform heterogeneously integrates silicon electronics and inorganic microlight emitting diodes (LEDs) into a 100-µm-scale package that is powered by and communicates with light. The devices are fabricated, packaged, and released in parallel using photolithographic techniques, resulting in ∼10,000 individual sensors per square inch. To illustrate their use, we show proof-of-concept measurements recording voltage, temperature, pressure, and conductivity in a variety of environments.