As the temperature of electronic devices increases, their failure rate increases. That is why electrical devices should be cooled. One of the promising cooling techniques is using Phase Change Materials (PCMs). A new passive temperature management technique, that involves the direct placement of PCMs on the chip, has been explored and developed. PCMs are potential temperature regulators that can store thermal energy and release it during melting and freezing respectively. PCM-based heat sinks can efficiently store the heat dissipated from the electronic components to delay the peak temperature of the electronic devices as much as possible and then release the stored energy during the off period. This paper compares the temperature distribution on a heat sink with and without PCM with different magnitudes of heat flux. Also, two different PCMs with different densities, namely salt-hydrate and wax, have been investigated in cooling electronic devices.

Parkinson’s patients suffer from severe tremor due to an abnormality in their central oscillator. Medications used to decrease involuntary antagonistic muscles contraction can threaten their life. However, mechanical vibration absorbers can be used as an alternative treatment. The objective of this study is to provide a dynamic modeling of the human hand that describes the biodynamic response of Parkinson’s patients and to design an effective tuned vibration absorber able to suppress their pathological tremor. The hand is modeled as a three degrees-of-freedom (DOF) system describing the flexion motion at the proximal joints on the horizontal plane. Resting tremor is modeled as dual harmonic excitation due to shoulder and elbow muscle activation operating at resonance frequencies. The performance of the single dynamic vibration absorber (DVA) is studied when attached to the forearm and compared with the dual DVA tuned at both excitation frequencies. Equations of motion are derived and solved using the complex transfer function of the non-Lagrangian system. The absorber’s systems are designed as a stainless steel alloy cantilevered beam with an attached copper mass. The dual DVA was the most efficient absorber which reduces 98.3%–99.5%, 97.0%–97.3% and 97.4%–97.5% of the Parkinson’s tremor amplitude at the shoulder, elbow and wrist joint.