In this talk, I would like to introduce three approaches in small scale thermal and mechanical science and engineering. The first part of the talk will focus on the utilization and characterization of nanosystems, i.e., carbon nanotubes and nanowires. In the second part, a novel method of measuring temperature and thermal conductivity of 2-D materials such as carbon nanotubes films and graphene at microscale level will be presented. This method involves with a cellular-level, high-resolution temperature sensing system using a micropipette thermocouple sensor. This microscale sensor measures the thermal response (transient temperature variation subject to modulated heat input) of biological samples; the measured data combined with mathematical models was used to determine the thermal conductivity. The data output can be used for early disease detection, which is derived from differences in thermal properties in an in vitro human melanoma model of progression as well as thermal properties of ductal carcinoma breast cancer. If time permits, recent advances in biological imaging technology using an ultrasound wave will be introduced. Ultrasound is one of the developing technologies that is broadly used in biomedical and manufacturing engineering. Ultrasound can provide fast, non-destructive mechanical property detection in materials with known basic physical properties such as density. The method can be used on hard materials, soft material, and tissue phantoms for effective bulk modulus and effective density mapping without any external stress on samples.